Merge branch 'postprocwork'

* postprocwork:
  postproc/postprocess: use av_strtok()
  postprocess: make some variables in pp_get_mode_by_name_and_quality() const
  postproc: simplify forwarding return codes
  libpostproc/postprocess: avoid some if()
  fate: add fate-filter-pp1

This is merged instead of just fast forward pushed due to a bug in the git hook
which does not allow commits to change filter-video.mak except merge commits.
filter-video.mak contains a few tabs, which are needed due to Makefile syntax

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