From commit dd74a851, to be exact. Now cap_ffmpeg.cpp should actually
build if HAVE_FFMPEG is true.

Also modified some gpu sources in a similar manner.

Need to go back at some point and fix this for real.

(cherry picked from commit dfe07df8)

Newer FFmpeg prohibits 4096x4096 MPEG-2, presumably because it violates
the standard.

http://git.videolan.org/gitweb.cgi/ffmpeg.git/?p=ffmpeg.git;a=commit;h=7fb87bc5f24b1be13269109506c05e4c54695b5e

(cherry picked from commit 424a7b0a)

Conflicts:
	modules/highgui/test/test_ffmpeg.cpp

(cherry picked from commit 3f3ae333)

While the FFmpeg video IO backend gets compiled even without it,
the tests (for both FFmpeg and video IO) don't. This should fix
that.

Linker dependencies to all OpenCV modules are invalid.
We should not include other bindings in this list (like "opencv_python").

Removed incorrect release of obtained colorspace. This fixes bug #3318 (updated commit for 2.4 branch)

Bug report and inspiration: http://code.opencv.org/issues/3328

Bug report: http://code.opencv.org/issues/3329