ActiveAE: reset fading flag when drained, paplayer waits on this
ActiveAE: only convert gui sounds if format has changed
ActiveAE: fix crash for multiple streams when transcoding
ActiveAE: fix determination when a stream is drained
ActiveAE: gapless and audiophile are best friends, revisit after we have new audio settings
Merge pull request #3153 from FernetMenta/aefixes

ActiveAE fixes