ext/ffmpeg/gstffmpegenc.c: Fix pad_link function to handle formats that ffmpeg returns as multiple caps structures.

Original commit message from CVS:
* ext/ffmpeg/gstffmpegenc.c: (gst_ffmpegenc_connect):
Fix pad_link function to handle formats that ffmpeg returns
as multiple caps structures.
* gst/videofilter/gstvideofilter.c: (gst_videofilter_chain):
Only complain if source buffer is _smaller_ than expected.
* gst/videoscale/gstvideoscale.c: (gst_videoscale_init),
(gst_videoscale_handle_src_event): Resize navigation events
when passing them upstream.
* gst/videotestsrc/gstvideotestsrc.c:
* gst/videotestsrc/gstvideotestsrc.h:
* gst/videotestsrc/videotestsrc.c:
* gst/videotestsrc/videotestsrc.h:
Rewrite many of the buffer painting functions to handle odd
sizes (for many formats, size%4!=0 or size%8!=0).  Most have
been verified to work with my video card.
* testsuite/gst-lint:  Add check for elements calling
gst_pad_get_caps() instead of gst_pad_get_allowed_caps().