- new AudioPort class
o wraps xine_audio_port_t* and deletes it automatically when it's not needed anymore
o holds the logic to create the correct audio port which is rather messy when you want a different device than configured for xine
-> should fix a race condition when the AudioOutput is deleted while xine_open is called in another thread
- use Solid to list OSS devices
- use KAlsaDeviceList to list ALSA devices
- when doing the gapless switch don't set m_mrl from the main thread to avoid races
- XineEngine keeps track of AudioOutputDevices now and keeps the info persistent in phononxinerc