Make playdar-core handle playback

[jwheare]

I've been vaguely following the discussion in IRC about doing this for other reasons, but another important reason is that it would greatly simplify web app client development. Currently setting up and managing sound manager is a bit of a chore, and prone to some oddities with flash.

This would basically require an HTTP api for playback. Play SID, pause current, and also a reverse notification mechanism, probably with a comet iframe and #hash communication.

Let's talk about this. :)