audio: Add simple parsers for m3u, pls, xspf and uri lists.
audio: Add simple parsers for m3u, pls, xspf and uri lists.

These parsers, and the detectors should probably be moved out at some point,
but for now the simple version of these will do.

SuperStarPL/mopidy,adamcik/mopidy,bencevans/mopidy,quartz55/mopidy,pacificIT/mopidy,hkariti/mopidy,quartz55/mopidy,jcass77/mopidy,pacificIT/mopidy,jmarsik/mopidy,ZenithDK/mopidy,ali/mopidy,hkariti/mopidy,pacificIT/mopidy,mokieyue/mopidy,adamcik/mopidy,diandiankan/mopidy,rawdlite/mopidy,swak/mopidy,SuperStarPL/mopidy,abarisain/mopidy,dbrgn/mopidy,bacontext/mopidy,dbrgn/mopidy,bencevans/mopidy,kingosticks/mopidy,adamcik/mopidy,SuperStarPL/mopidy,SuperStarPL/mopidy,hkariti/mopidy,tkem/mopidy,bencevans/mopidy,jmarsik/mopidy,diandiankan/mopidy,mokieyue/mopidy,swak/mopidy,rawdlite/mopidy,woutervanwijk/mopidy,bacontext/mopidy,kingosticks/mopidy,liamw9534/mopidy,bencevans/mopidy,bacontext/mopidy,tkem/mopidy,woutervanwijk/mopidy,mokieyue/mopidy,ali/mopidy,mokieyue/mopidy,glogiotatidis/mopidy,rawdlite/mopidy,diandiankan/mopidy,ali/mopidy,quartz55/mopidy,ZenithDK/mopidy,dbrgn/mopidy,tkem/mopidy,vrs01/mopidy,tkem/mopidy,ZenithDK/mopidy,priestd09/mopidy,priestd09/mopidy,bacontext/mopidy,pacificIT/mopidy,abarisain/mopidy,vrs01/mopidy,mopidy/mopidy,jodal/mopidy,jmarsik/mopidy,mopidy/mopidy,jodal/mopidy,glogiotatidis/mopidy,jcass77/mopidy,priestd09/mopidy,jmarsik/mopidy,vrs01/mopidy,swak/mopidy,liamw9534/mopidy,swak/mopidy,dbrgn/mopidy,mopidy/mopidy,diandiankan/mopidy,jodal/mopidy,ZenithDK/mopidy,rawdlite/mopidy,glogiotatidis/mopidy,glogiotatidis/mopidy,jcass77/mopidy,hkariti/mopidy,vrs01/mopidy,kingosticks/mopidy,quartz55/mopidy,ali/mopidy