Screen for Linux rebuilt and tested with LosslessMovieWritingTest.m

-> Screen for 64-Bit Octave on Linux rebuilt and tested.
-> Small Octave 3.2 backwards compatibility fix for
   LosslessMovieWritingTest.m
-> All 8/16 bpc lossless movie encodings verified to work with test.
Screen: Apply filter-caps also during recording with GStreamer+camerabin1

Now that this is an opt-in via recordingflags 4096, we can also
apply during recording, as the user is in control here.

-> Screen for 64-Bit Octave on Linux rebuilt and tested.
VideoCaptureDemo: Allow optional bpc > 8 capture testing.

Via new optional 'bpc' parameter.