reformatted source to kernel style
use pa_mainloop_iterate instead of own implementation

pulse audio provides it's own convenience function to
iterate the mainloop, no need to use a custom one.
use timestamps returned by pulseaudio instead of system time

pulseaudio provides timing information for the stream, we use
that instead of system time.
Revert "added support for older versions of ffmpeg"

This reverts commit 385d5472246632b2e344e35670c9c67e47869c3f.