bugfixes and improvements in the image acquisition

- added interface to the Kinect2 libraries
- added desired resolution as parameter for OpenNIEngine
- more sensible way of finding suitable resolutions in OpenNIEngine
- now also works properly with .oni files
- extended support for "invalid pixels" in the depths
- fixed windows build bug by removing <values.h> from ITMVisualisationEngine_CPU.cpp
- other minor compilation bugs on odd systems...
Merge branch 'master' of https://github.com/victorprad/InfiniTAM

Conflicts:
	InfiniTAM/Engine/OpenNIEngine.cpp