mpd: Update event handling to warn about unknown events
mpd: Update event handling to warn about unknown events

mokieyue/mopidy,ZenithDK/mopidy,adamcik/mopidy,jcass77/mopidy,vrs01/mopidy,vrs01/mopidy,mokieyue/mopidy,jcass77/mopidy,mopidy/mopidy,mopidy/mopidy,jcass77/mopidy,tkem/mopidy,tkem/mopidy,kingosticks/mopidy,vrs01/mopidy,ZenithDK/mopidy,jodal/mopidy,mopidy/mopidy,kingosticks/mopidy,adamcik/mopidy,adamcik/mopidy,jodal/mopidy,ZenithDK/mopidy,vrs01/mopidy,mokieyue/mopidy,tkem/mopidy,jodal/mopidy,tkem/mopidy,kingosticks/mopidy,ZenithDK/mopidy,mokieyue/mopidy