51 Fix path to libz library
#51 Don't use BAT files when not building with VS
#51 Fetch FFmpeg binaries built by MinGW too
Merge branch 'master' into 51_MSYS

* master:
  Fix aspect ratio of the movie in sample
  WIP
  Temporary save
#51 Fix FFmpeg lib suffix on non Windows target
Merge branch '51_MSYS'