Fix hardware detection on aix.
avconv: Match stream id

Quite useful to select by pid in MPEG-TS.
Merge remote-tracking branch 'qatar/master'

* qatar/master:
  avconv: Match stream id

Conflicts:
	cmdutils.c
	doc/fftools-common-opts.texi

See: ea07063fd82686af3fabb45e5ed10aa48d084d61
Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge remote-tracking branch 'cehoyos/master'

* cehoyos/master:
  Fix hardware detection on aix.

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