Merge commit 'b452d5ae'

* commit 'b452d5ae':
  mpeg4videodec: move mpeg4-specific bug detection from h263 generic code to mpeg4

Conflicts:
	libavcodec/h263dec.c

not merged, the header decode function is not the right place
See: 6c9b82b6Merged-by: Michael Niedermayer <michaelni@gmx.at>