OpenNI2 driver modification including device serial number.
Merge pull request #3 from KMiyawaki/OpenNI2_mod

OpenNI2 driver modification including device serial number.
Restructuring the classes related to OpenNI2 functionality after the changes pushed by KMiyawaki.
Bug fixed when MRPT has NOT OpenNI2. Old comments cleaned.
Merge pull request #61 from EduFdez/master

Restructuring the OpenNI2 classes