Pull development snapshot for color space and gpgpu stuff.

* First batch of color space conversion stuff.
* First batch of GPUmat/CUDA GPGPU stuff.
* ColorCal for Octave support.
* Use of thread-type parameter for GStreamers multi-threaded video decode.
* Various fixes and improvements, but not compiled for all platforms.

Both are unfinished wip, just for alpha-testers.