* commit 'c334c113':
  vf_scale: switch to an AVOptions-based system.

Conflicts:
	doc/filters.texi
	libavfilter/avfilter.c
	libavfilter/vf_scale.c

scale keeps using our shorthand system due to the alternative not
supporting the more complex syntactical things like 1 parameter
dimensions
Merged-by: Michael Niedermayer <michaelni@gmx.at>