Faststart via FFMPEG

- Make sure you're running an up to date build of ffmpeg
- Replaces the need to run QTFastStart while still making a more
streaming friendly file. Not going to implement an option for this, it
will be a forced default
- QTFastStart will remain part of the script to be used on files that
aren't created by this script. The move-moov option will still apply to
these files