Use glob and fs.unlink instead of shelling out to rm.
trying h.264 again
trying ogv
slow down a bit
Merge pull request #13 from tec27/noexec_rm

Use glob and fs.unlink instead of shelling out to rm.
Use JPEG for client posting instead of PNG.

This leaves the glitch -> PNG step intact, so ffmpeg is still dealing
with PNGs. This also fixes a number of bugs in the media conversion
process, and removes unnecessary setImmediate calls.