A lot of updates, all necessary to get the native protocol ported:

A lot of updates, all necessary to get the native protocol ported:

* add an int64_t argument to pa_asyncmsgq because it is very difficult to pass 64 values otherwise
* simplify subclassing in pa_object
* s/drop/unlink/ at some places
* port the native protocol to the lock-free core (not tested, compiles fine)
* move synchronisation of playback streams into pa_sink_input
* add "start_corked" field to pa_sink_input_new_data
* allow casting of NULL values in pa_object

git-svn-id: file:///home/lennart/svn/public/pulseaudio/branches/lennart@1562 fefdeb5f-60dc-0310-8127-8f9354f1896f