GLMediaPlayer: pause() -> pause(boolean flush): Allowing to flush buffers, next frame after play() will provide new frame. Added API doc.
ffmpeg_impl_template: Remove DEBUG line ..
FFMPEGMediaPlayer: Handle use-case of having [av|sw]resample lib, but not compiled for it -> pass

Scenario ffmpeg-0.10, where we are not prepared (compiled-in) for sw-resample support.
Don't use if compiled in version (CC) is < 0 (n/a), and allow to pass at load time.