j2kdec: update to new buffer API
linopencore-amr: fix compile
libvorbisdec: update to new API
loco: fix compile

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
paf: update to new API
proresdec: update to new API
tiff: resolve conflicts

TESTME: some particular attention is needed on metadata
vmdav: resolve conflicts

Note: not sure if avcodec_get_frame_defaults() is needed for the local AVFrame.
qpeg: resolve conflicts (FIXME/TESTME).

 - current is an attempt to honor changes in a0db7424
 - need to be tested with fate + should be tested with V-codecs/QPEG/Clock.avi
 - potential overlapping refdata and dst memcpy in qpeg_decode_inter()
 - on a side note, AVFrame ABI issue + no proper AVFrame init (since no
   alloc with the API) but that is problematic in the fork as well
truemotion1: resolve conflicts
truemotion2: resolve conflicts