Added FindOpenNI2.cmake search module.
Added OpenNI2 wrapper stub based on WillowGarage files.
Added build_OpenNI2 CMake option.
Added OpenNI 2 grabber class.
Added more OpenNI2 grabber source files.

Removed unused files.
Added OpenNI2 viewer app to visualization.
Fixed integration errors and temporarily disabled one function for testing.
Worked on OpenNI2 device manager.
Fixed link errors.

Forgot to include pcl_exports.h
Fixed compiler errors with DepthImage callback.
Changed debugging statements.
Changed default viewpoint in OpenNI2 viewer code.
Removed unused files from CMakeLists.
Fixed file naming inconsistencies.
Added additional abstraction around OpenNI wrapper data types.

This should allow switching between OpenNI 1/2 wrappers.
Added command to copy OpenNI2 redist folder to bin directory.
Added OpenNI2 library checks when building.
Added OpenNI 1.x/2.x switches.
Masked oni_grabber errors when the OpenNI 1.x wrapper is not used.
Stopped building broken apps when only OpenNI2 is available.