Moved AudioDevice::setupWidget into its own class AudioDeviceSetupWidget
which logically should belong to the GUI (unfortunately the include
structure does not make this obvious).
For the ALSA driver there is an implementation AudioAlsaSetupWidget
which provides a combo box for selection of the card and device.
All other driver widgets have been changed to inherit from
AudioAlsaSetupWidget but have not been changed otherwise.
SetupDialog has been adjusted to keep a map of AudioAlsaSetupWidgets
now.
There have been some problems with the threading logic in the
AudioPulseAudio backend resulting in an endless loop when quitting LMMS.
Furthermore allocated PulseAudio resources were not freed properly.
Thanks to Armin Kazmi <armin.kazmi@tu-dortmund.de> for pointing out
this issue.
(cherry picked from commit 168805745e)