Introducing AbstractPipeline::s_init and AbstractPipeline::s_deinit signals (including Lua bindings) as first step to simplify writing entire pipelines as Lua scripts. The signals are emitted as blocking calls (via triggerSignal()) and can be used by Lua scripts to run (de)initialization code in callback functions.
This was tested with the volumerendererdemo.lua pipeline.

* Added automatic copy of inspect.lua to binary directory to CMake build scripts
* Added AbstractPipeline::getProcessor(std::string&)
* Added ScopedSynchronousGlJobExecution guard to Lua command execution to ensure having an OpenGL context present
* Fixed ordering in CampvisApplication::deinit()

signal::connect() now checks whether there exists already a connection to the same slot.

In this context, removed some redundant signal-slot connections.

refs #386

refs #386

refs #386

* Tied tgt::OpenGLJobProcessor and tgt::OpenGLGarbageCollector closer together regarding OpenGL garbage collection
* AutoEvaluationPipeline checks for valid OpenGL state after each processor call (only in debug)

* Fixed AutoEvaluationPipeline missing some updates
* Fixed AutoEvaluationPipeline::executePipeline() to execute processors too often
* Fixed ParticleFlowRenderer overwriting bound FBO
* Added Debug checks to tgt::FramebufferObject and tgt::Shader to print warnings when FBO/Shader activation would overwrite an already active FBO/Shader

Moved AbstractJob and OpenGLJobProcessor from campvis-core to tgt and adapted and cleaned up all necessary includes/references.

The new OpenGL wrapping API allows for full multi-threaded access to OpenGL contexts. Instead of one single thread scheduling all OpenGL jobs for all contexts, the new GlContextManager allows for OpenGL access from multiple threads while ensuring that each OpenGL context is acquired by only one thread at a time.

Detailed list of changes:
* tgt::GlContextManager keeping track of which threads acquire which OpenGL contexts and which threads currently have a context acquired.
* OpenGLJobProcessor does no longer schedules and execute the OpenGL calls for all existing contexts, but only for one single context that can be used for background tasks or other jobs that explicitly need a valid OpenGL context.
* AbstractPipeline now implements the Runnable interface and thus runs in it's own thread. This thread also owns the pipeline's OpenGL context.
* AbstractPipeline has a new pure virtual method executePipeline() that has to perform all computations done by the pipeline.
* AbstractPipeline now takes directly care of calling Painter::paint() of the pipeline's canvas (instead of signalling the Painter). However, the Painter interface needs further cleanup.
* AutoEvaluationPipeline was adapted to the new AbstractPipeline API, hence executing processors is no longer delegated to the OpenGLJobProcessor or the SimpleJobProcessor but entirely done in AutoEvaluationPipeline::executePipeline() and thus in the pipeline's thread.
* Adjusted CampVisApplication, DataContainerInspectorWidget, and GeometryTransferFunctionEditor to the new API.

* Fixed possible endless loop in event evaluation of AbstractPipeline.
* Fixed 4-channel image rendering in datacontainerinspector.frag.

Replaced DataContainer::s_dataAdded<const std::string&, DataHandle> with DataContainer::s_dataAdded<std::string, DataHandle>.

According to Visual Leak Detector, CAMPVis is now memory leak free. :)

* Slight changes to the API: renamed signal::trigger() to signal::triggerSignal() and signal::queue() to signal::queueSignal()
* Replaced all sigslot signal emits through operator() with emits through emitSignal() to enable debug feature.
* Fixed a possible race condition when deleting a GeometryTransferFunction and its editor window at the same time (as this will happen from different threads).

refs #384

Removed all occasions where references to DataHandles were used, since especially their use in signals may lead to segfaults or other undesired behavior.

Removed unlockInExtraThread flag from AbstractProcessor::process() - this is no longer needed as signal handling is done asynchroneously now anyway.

#ref 384

Conflicts:
	core/pipeline/abstractprocessor.cpp

Conflicts:
	core/pipeline/abstractprocessor.cpp
	core/pipeline/abstractprocessor.h

To now, each property hat an _invalidationLevel field that was evaluated by processors when the property had changed in order to determine what has to be done. However, since properties could also be owned by other classes, this design was semantically misleading.
Therefore, it was removed with this commit and replaced by the invalidation map of each processor. Now, this per-processor mapping of property -> invalidation level is managed by the processor itself. Furthermore, the invalidation level is no longer setup during property creation but during AbstractProcessor::addProperty(), which also makes much more sense.

ATTENTION: Due to these intrusive API changes, the code of all processors and other classes handling properties needs to be changed. As a reminder, the implementation of addProperty() also now takes a reference instead of a pointer, so that old code does no longer compile.

refs #542

Refactoring AbstractProcessor::process() for clearer semantics and better and more uniform handling of invalidation levels:
 * AbstractProcessor::process() now calls updateShader(), updateProperties() and/or updateResult() with respect to the current invalidation level
 * each processor shall no longer override process() but the updateXYZ() methods, at minimum updateResult()
 * AbstractProcessor::process() takes care of (un)locking the processor itself (no need to do this from the outside anymore)

Further implicit changes:
 * Removed redundant HasPropertyCollection::updateProperties()

* Moving to Apache 2.0 license
* Updated AUTHORS.txt

Work on Issue #44: Removed GLContext interface and merged functionality into GlCanvas. Introducing abstract (Qt-free) tgt::GlContextManager interface, being implemented by tgt::QtContextManager. Further clean up of related code.

Refactoring pipeline concept #2: Got rid of distinguishing between AbstractPipeline and VisualizationPipeline. Every AbstractPipeline is also a VisualizationPipeline. However, AbstractPipeline does not care about evaluating its components - this has to be implemented in its subclasses.
AutoEvaluationPipeline subclasses AbstractPipeline and automatically evaluates the pipeline by listening to the signals of its components and calling the corresponding process() methods.

introducing AbstractProcessor::updateProperties(DataContainer&) which is automatically called by AbstractPipeline when a processor invalidates its INVALID_PROPERTIES flag

* fixed transfer function shader
* let processor unlock call after execution be handled by seperate thread

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@494 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

further step to OpenGL 3.3 core compatibility in core and modules: Got rid of glPush/PopAttrib in processors, added asserts for correct OpenGL state after processor execution

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@493 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

 * Moved destruction of ReferenceCounted object to seperate thread (thus unloading rendering thread)
 * integration of OpenGL garbage collector into OpenGLJobProcessor (finally, you don't need to care anymore whether your code might call a GL object destructor and hence needs an OpenGL context)
 * changed DataContainer implementation from mutex/lock to concurrent container
 * fixing improper order of GL object deinitilization on program exit

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@492 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@477 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

Revised InvalidationLevel concept: InvalidationLevels now directly belong to an AbstractProcessor and are considered to be thread-safe. Furthermore the different levels now really act as single flags that are set (invalid) or unset (valid) individually.

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@464 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

 * Pipelines evaluate themselves
 * removed the PipelineEvaluator
 * adapted all demo pipelines except OpenCLPipeline

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@462 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@446 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

* Introducing SimpleJobProcessor for dispatching non-OpenGL-related jobs

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@445 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

* added InvalidationLevel::INVALID_PROPERTIES level
* added HasPropertyCollection::updateProperties() method being triggerd upon INVALID_PROPERTIES invalidation

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@423 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

* implemented automatic connection of AbstractProcessor::s_invalidated signal

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@382 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@346 bb408c1c-ae56-11e1-83d9-df6b3e0c105e

* added AbstractPipeline::addProcessor() and VisualizationPipeline::addEventHandler() convenience methods
* some refactoring of property names

git-svn-id: https://camplinux.in.tum.de/svn/campvis/trunk@344 bb408c1c-ae56-11e1-83d9-df6b3e0c105e