* Disabled MSVC warnings when building freetype
* Added support to copy ITK libraries

* Added modules/modulesapi.h with CAMPVIS_MODULES_API definition (MSVC __declspec switch)
* Updated modules/CMakeLists.txt to allow shared build
* Added CAMPVIS_MODULES_API to every non-templated class definition in campvis-modules

Fontrendering

See merge request !105

* Cleaned up FontAtlas and completed documentation
* Cleaned up TextRenderer, added customizable font file, added exception handling
* Added two OpenSource default fonts (FreeSans and Bitstream Vera Mono)

* Introducing TextRenderer processor that renders a simple text using the FontAtlas
* Introducing FontRenderingDemo pipeline

* Added freetype2 as external library
* Drafted FontAtlas class as simple interface to render text using OpenGL

Workflow support

See merge request !104

Introducing workflowdemo module showing a demo implementation on how to use the CAMPVis workflow interface.

refs #13

* GenericImageReader now has a property for the target image ID
* Removed all the different setters for the URL/target image ID, as you should use the corresponding properties directly.

* Workflow stages now store the visibility of pipeline canvases
* Extended PipelineFactory to also hold creator functions to create workflows
* CampVisApplication now creates and initializes workflows when launched with "-w WorkflowName" parameter

refs #13

The WorkflowControllerWidget resides as new tab on the right-hand dock area of the main window and allows to interact with an AbstractWorkflow instance.

refs #13

Started drafting an AbstractWorkflow class to support generic and straight-forward implementation of entire workflows.
A workflow is a state machine represented by a graph, where each node defines one workflow stage and each edge one transition from one stage to another. The whole workflow is furthermore defined by the set of DataContainers and Pipelines active during the different states.

refs #13

Introducing virtual method AbstractData::getTypeAsString() to let every data type return a string representation of it's type to be shown in the GUI. Hence, we don't need the static if-then-else block in DataContainerTreeWidget anymore.

* Added new common base class RunnableWithConditionalWait that directly includes the std::condition_variable
* RunnableWithConditionalWait::stop() notifies the condition variable repeatedly as long until the thread has stopped. This avoids program hangs at shutdown due to race conditions.

* Improved appearance of PipelineTreeWidget
* Fixed IntPropertyWidget and FloatPropertyWidget recursively setting the widgets value, when the change event comes from the widget itself

Various stuff

See merge request !103

Now it is possible to create CAMPVis images with three dimensions but only a single slice (formerly automatically deduced as 2D image). Adapted/fixed some further code.

refs #613

* cleaned up cgt::Texture's constructors: only two left - to create an empty texture or a non-empty one
* cgt::Texture will no longer hold a copy of the image data in local memory
* removed a lot of redundant/confusing methods
* no longer needed to call uploadTexture() even though you don't want to upload sth.
* Adapted all known code to the new interface
* Removed cgt::TextureReaderDevil

refs #613

* Introducing cgt::Matrix4<T>::getXYZRotation() (one method for each X, Y, Z)
* Introducing cgt::Matrix4<T>::getTranslationPart()

* Added GL_UNIFORM_BUFFER and GL_SHADER_STORAGE_BUFFER targets to cgt::BufferObject

* Fixed DataSeriesSplitter::updateProperties()
* Fixed VolumeExplorer's camera ID not being dependent on output image name
* Added early return to AbstractProcessor::invalidate(level) if level == 0

* Introducing DataSeries type (like ImageSeries but holding AbstractData, ImageSeries should be replaced some time)
* Fixed cgt::dmatX typedefs

Both classes now have a mutex protecting its shared fields. One global mutex may not be the most efficient implementation but at least is reliable and easy to follow.

closes #598