local: Re-add progress helper and log flushes.
local: Re-add progress helper and log flushes.

Refactored the progress helper to be used in batching flushes in addition to
logging.

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