Rename ScreenSharing to ScreenSharingServer

Ignore-this: 2fbe1d7d53b4689b6c171b4fe5cb34de

darcs-hash:20130118133039-58252-c67c2250bf005a51b7d24a4ec1ceaed0fa89cb17
Update list of exported classes

Ignore-this: 57b430b7feb10b5ccd5387195f2a26ae

darcs-hash:20130118133456-58252-964c83c899ed09cdf69c1bd9dc78f08662981bb9
Provide direct access to stream types on MediaStreamRegistry

Ignore-this: 5736d988600a99189d5b3fd9f0072d5e

darcs-hash:20130118162613-b22ec-b068e3152372b513e720a69ba4bbd6340e2a7e5d