Fix for the media tests and a new bug related with Pulse

[Martin Di Paola]

Well, i fix the problem with the tests in the category 'media'. In resume, the 'dispatch_events' was removed from the Player class and that causes that the test fail throwing a exception.

The solution was replace that call by 'pyglet.app.platform_event_loop.dispatch_posted_events()'. Obviously this is not efficient but it is fine for the test (and emulate the previous code)

After this fix, the tests still failing. The problem was that the sources used (from the media.procedural package) implements the method '_get_audio_data' instead of 'get_audio_data'.
The final patch is attached.

With this, the tests pass except the media.PLAYER_PAUSE_QUEUE test. For some reason, after playing the sound, a critical error is raised. Here is the output

Assertion 's' failed at pulse/stream.c:2351, function pa_stream_trigger(). Aborting.
Abortado (`core' generado)

Someone can confirm this? I am using Pulse as a driver in a Ubuntu 12.04.

Bye!