Removed --input-device flag.

Instead of requiring --input-device flag to indicate that input is a
device, just auto-detect. If input is a block device, look to see where
it's mounted.
Changed audio codec to AAC.

AAC audio is compatible with Roku, PS3, Samsung TVs, and many other
devices. AC3 (what was being used previously) in an MP4 works on the
PS3, but not much else.
Explicityly specifiy h.264 video encoding.

Add --encoder x264 to HandBrakeCLI.