Add a PulseAudio output driver.
It uses libpulse's synchronous API, to output to PulseAudio
without using libao.
Fix pulse audio output driver in daemon mode.
libpulse was initialized before the fork. This caused calls to libpulse
made after the fork fail.
Now initialize lib pulse when we need it, after the fork.
pulseaudio: fix option parsing
pulseaudio: Make the application name configurable

If no name is specified, use the AirPlay access point name.
Merge pull request #223 from plietar/pulseaudio

Add a PulseAudio output driver, courtesy of Paul Lietar