When giving up control to Jack, module-jack-sink and module-jack-source should be loaded

[ngoonee]

Hi, reference the issue as I brought up in  https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-October/005280.html

Also reference some implementation help from Jack2 dev nedko in  https://tango.0pointer.de/pipermail/pulseaudio-discuss/2009-October/005361.html

Basically, I believe module-jack-sink/source should be automatically loaded when jack says "I want the sound card".

Ideally, this would also move all streams to module-jack-sink/source (else some applications ex. totem just hang due to their sound output not being processed), but that's bonus and can be set pretty easily through priorities/defaults.