ffwavesynth: update to new buffer API

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
g729: update to new API
indeo5: fix compile
roqvideodec: resolve conflicts
pictordec: resolve conflicts
mdec: resolve conflicts
tiertexseqv: resolve conflicts
smacker: resolve conflicts
vb: resolve conflicts
vqavideo: resolve conflicts
xl: resolve conflicts
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