OTHER: Build nycli agains correct readline
OTHER: Rename broadcast playlist_changed to changed.

This makes it consistent with other broadcast names.
Make xmmsc_connect async under emscripten.
Always use tcp sockets under emscripten.
Define some constants that are missing in emscripten.
Emscripten always "fails" on async connect()
Include emscripten glue code: main loop and result handler.
Autogenerate a Javascript client library with Emscripten.
Added sample Javascript client.