Webcam javascript app notes

We have a server providing a chunked multipart message.


 * 1) this must not fall afoul of cross site scripting protections, so run from the same server
 * 2) firefox supported a multipart attribute to the XHR and it's been removed since firefox 22, don't use that (it was firefox only anyway - see bz 843508)

XMLHttpRequest (XHR) with progress events are the way to go.

Some helpful things:
 * https://github.com/phoboslab/jsmpeg - MPEG1 with javascript decoding (just for the javascript foo, if we go to a real video format better to just use webm, unless we can't encode in real time).