Made custom MEncoder settings safer
Made vcodec safe to use in custom MEncoder options
Formatting
MEncoderVideo:

- The code that keeps videos to mod4 is more accurate
- Video filter options are one string instead of potentially two, which fixes conflicts between some renderer settings like KeepAspectRatio and MaxVideoWidth/Height
Merge branch 'master' of github.com:UniversalMediaServer/UniversalMediaServer