* Chrono was added in boost 1.47.0, so changed minimum version to match.

*also added a find_openni2 macro to PCLConfig.cmake.in to allow external users of PCL to find the OpenNI 2 libraries. This is a duplicate of the code in FindOpenNI2.cmake.

* This is not an exceptional event and always occurs for file devices. Print error message instead.

* The convertTo..PointCloud methods used statically allocated buffers to resize images, causing a data race if multiple deices tried to create point clouds simultaneously. Switched to using member buffers for each grabber.

* Fixed assignment in conditional test
* Removed unused argument to focal length getters
* Removed 'register' keywords that do nothing.

* Changed default viewpoint for OpenNI 2 viewer app. Needed to look down +Z axis to see point cloud.

* Depends on pcl/io/openni_grabber.h and does not work with OpenNI 2.x grabber yet

… alignments.

* /usr/include/openni2 is a common install location for unofficial OpenNI2 deb packages.