use proper models instead of munging with mongo.

Now we do not depend on Caspa anymore to ingest stuff.
MD5: emit error if file is not found.
FFmpegInfo: handle when bitrate is not available.

For some videos we can get 'N/A' instead of a number.
FFmpegInfo: fix aspect ratio calculation.

when that value is not available infer it from the video size.
jobs: identify '.jpeg' as image too.
Thumbnail: correctly calculate -ss param to ffmpeg
move queue initialization outside of Patero. Use proper path variables
instead of global.
move creation of Media on Caspa outside of Patero, just signal that
the transcoding is done.
adds a GLib Redis listener.

can't believe it took so long to make something so simple.
Backbone.Collection: fixes __getitem__
Backbone: two way Redis binding that kind of works
RedisListener: make it inheritance friendly.

Sometimes, it's like having Peggy Lee all over the place singing "Why
don't you do right" when you open the editor.