g2meet: reset dimensions on header parsing errors
g2meet: more graceful cursor loading
g2meet: do not leak buffers
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  g2meet: do not leak buffers
  g2meet: more graceful cursor loading
  g2meet: reset dimensions on header parsing errors

Conflicts:
	libavcodec/g2meet.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
alacenc: Fix missing sign_extend()

Possibly fixes Ticket2497

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