Added visualization of point cloud data from Kinect camera. Colorized point cloud visualization to follow soon.

corrected a compile warning in Wayppoint.cc, made adaptions to Freenect for the current revision of the code (update libfreenect repository!), commented out pixhawk poi mavlink code - needs fixing

Changed status message in qgroundcontrol.pro, fixed compile error in class Freenect (void* did not work)

Switched from flite for speech on the Mac to built-in MacOSX speech synthesizer. Fixed build system for 64-bit builds (using official SDL.framework, and Qt frameworks).