GitLab

- First step for integration of the analytics framework in the collectagent
- QueryEngine and REST API integration still missing
- Proper testing still to be done
- Added a probe function: the global config file is scanned before
initialization, and if no data analytics plugins are requested, no
sensor navigator is built

- Added some more indentation to make the configurations more readable
- Fixed one more warning in dcdbquery

- Sensor caches across DCDB are now managed by the CacheEntry
implementation under "common"
- Provides utility methods to perform averages, checks, get views etc.
- SensorCache class in collectagent kept due to its libdcdb dependencies

- Added a 'common' directory where all shared code has been placed
- Analytics package has been moved out of dcdbpusher, now has its own makefile
- Some renaming here and there for uniformity