Add support for RTMP streaming to JavaScript SDK.

SoundManager2 does not support RTMP streaming. Removed SoundManager2
and replaced it with a minified version of AudioManager. Instead of
using the /tracks/:track_id/stream endpoint, which redirects to an
HTTP stream, the JavaScript SDK now uses the /tracks/:track_id/streams
endpoint to get all available stream URLs. HTTP is used if available,
otherwise RTMP is used.

Modified tests to private functions for preparing stream URLs. This
commit introduces changes to private / utility functions such as
SC._prepareStreamUrl.
Use window.location.port to make it easier to run tests locally (on servers running on non-80 ports)
Light refactoring
Monkey patch a stop method on players (to mimic soundmanager functionality)