h264: Replace mpegvideo-specific MAX_PICTURE_COUNT by private define
h264: Replace mpegvideo-specific MAX_THREADS by private define
h264: Remove MotionEstContext and move the relevant fields to H264Context

Unused buffers scratchpad and temp have been dropped too.
mpegvideo: move mpegvideo formats-related defines to mpegutils.h
Merge commit '5d1c2e53ab3ce27b48c138d22bb01ff8e8304f27'

* commit '5d1c2e53ab3ce27b48c138d22bb01ff8e8304f27':
  h264: Replace mpegvideo-specific MAX_PICTURE_COUNT by private define

Conflicts:
	libavcodec/h264.c
	libavcodec/h264_ps.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'e3c2d0f3d41f79f7be7ba944aaca2e287c7d5c7c'

* commit 'e3c2d0f3d41f79f7be7ba944aaca2e287c7d5c7c':
  h264: Replace mpegvideo-specific MAX_THREADS by private define

Conflicts:
	libavcodec/h264.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '136034d86b5cb1819a2c3e6ecdfeb05dcba7140d'

* commit '136034d86b5cb1819a2c3e6ecdfeb05dcba7140d':
  h264: Remove MotionEstContext and move the relevant fields to H264Context

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'e0c16e4e3259cf50b5bac4c23bb6e517f397c74b'

* commit 'e0c16e4e3259cf50b5bac4c23bb6e517f397c74b':
  mpegvideo: move mpegvideo formats-related defines to mpegutils.h

Conflicts:
	libavcodec/h264_cabac.c
	libavcodec/h264_cavlc.c
	libavcodec/h264_mvpred.h
	libavcodec/svq1enc.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/vaapi: fix pointer types after H264Picture changes

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/vdpau: fix ff_vdpau_get_surface_id() argument after H264Picture

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>