Worker: first draft for the Server abstraction

Implement #signin and #signout
Worker: first draft of the websocket encapsulation for the Server object
Worker: send data to the server via the Server object
Worker: add a XXX comment
Worker: wait for the config before trying to auto connect
Worker: implement an autoconnect method for Server
Worker: remove the _presenceSocket crap

\o/
Worker: replaced microevent with backbone-events-standalone
Hide the timeout/establish view when a timed out window gets an incoming call
Don't send hangup when we're in the timeout state - we've already sent one.
Move testing for the call state when hanging up into the call model.
Remove last call.hangup() caller, and mark it clearly as an internal-only API.
Worker: moved server event listeners to _setupServer
Worker: moved all http operations to a new HTTP module
Change back to just one hangup function and add a few comments for future clarity/refactorings.
Merge pull request #215 from tOkeshu/worker-server-abstraction

Refactor the worker to have a Server abstraction
Worker: correct usage of importScripts
Merge pull request #219 from n1k0/import-scripts-fix

Worker: correct usage of importScripts
Merge branch 'master' into fix_timeout_view
Merge pull request #218 from Standard8/fix_timeout_view

Ensure we hide the establish/timeout view at the right times, and don't send hangup in timeout state