mpdstats: update rating on 'stop' (e.g. last song in playlist)
mpdstats: update rating on 'stop' (e.g. last song in playlist)

Fixes #772

ruippeixotog/beets,m-urban/beets,madmouser1/beets,Andypsamp/CODfinalJUNIT,MyTunesFreeMusic/privacy-policy,ruippeixotog/beets,mathstuf/beets,kelvinhammond/beets,gabrielaraujof/beets,untitaker/beets,SusannaMaria/beets,Freso/beets,ruippeixotog/beets,sampsyo/beets,Wen777/beets,xsteadfastx/beets,drm00/beets,jmwatte/beets,tima/beets,MyTunesFreeMusic/privacy-policy,dfc/beets,moodboom/beets,bj-yinyan/beets,kelvinhammond/beets,sampsyo/beets,PierreRust/beets,swt30/beets,diego-plan9/beets,Wen777/beets,lengtche/beets,mried/beets,Kraymer/beets,dfc/beets,ibmibmibm/beets,sampsyo/beets,jackwilsdon/beets,mried/beets,shanemikel/beets,ttsda/beets,artemutin/beets,lightwang1/beets,jackwilsdon/beets,marcuskrahl/beets,tima/beets,m-urban/beets,parapente/beets,beetbox/beets,YetAnotherNerd/beets,Andypsamp/CODfinalJUNIT,bj-yinyan/beets,moodboom/beets,jmwatte/beets,ibmibmibm/beets,parapente/beets,LordSputnik/beets,kareemallen/beets,m-urban/beets,m-urban/beets,jcoady9/beets,ibmibmibm/beets,Andypsamp/CODfinalJUNIT,Dishwishy/beets,jcoady9/beets,Freso/beets,beetbox/beets,randybias/beets,shamangeorge/beets,shamangeorge/beets,andremiller/beets,randybias/beets,swt30/beets,gabrielaraujof/beets,MyTunesFreeMusic/privacy-policy,bj-yinyan/beets,dfc/beets,MyTunesFreeMusic/privacy-policy,untitaker/beets,diego-plan9/beets,asteven/beets,lightwang1/beets,lengtche/beets,LordSputnik/beets,kelvinhammond/beets,mosesfistos1/beetbox,kareemallen/beets,multikatt/beets,shamangeorge/beets,swt30/beets,swt30/beets,Dishwishy/beets,pkess/beets,mosesfistos1/beetbox,moodboom/beets,shanemikel/beets,untitaker/beets,mried/beets,madmouser1/beets,shanemikel/beets,arabenjamin/beets,artemutin/beets,arabenjamin/beets,parapente/beets,PierreRust/beets,drm00/beets,Andypsamp/CODfinalJUNIT,madmouser1/beets,randybias/beets,marcuskrahl/beets,SusannaMaria/beets,gabrielaraujof/beets,ruippeixotog/beets,imsparsh/beets,pkess/beets,diego-plan9/beets,andremiller/beets,mathstuf/beets,marcuskrahl/beets,shanemikel/beets,bj-yinyan/beets,Andypsamp/CODjunit,dfc/beets,marcuskrahl/beets,Freso/beets,mosesfistos1/beetbox,SusannaMaria/beets,beetbox/beets,jmwatte/beets,Andypsamp/CODjunit,lengtche/beets,untitaker/beets,Kraymer/beets,PierreRust/beets,shamangeorge/beets,andremiller/beets,mosesfistos1/beetbox,Kraymer/beets,beetbox/beets,jackwilsdon/beets,PierreRust/beets,multikatt/beets,gabrielaraujof/beets,Kraymer/beets,LordSputnik/beets,LordSputnik/beets,madmouser1/beets,xsteadfastx/beets,Andypsamp/CODfinalJUNIT,sadatay/beets,Andypsamp/CODjunit,asteven/beets,drm00/beets,xsteadfastx/beets,Dishwishy/beets,sadatay/beets,pkess/beets,ttsda/beets,sampsyo/beets,kelvinhammond/beets,tima/beets,randybias/beets,jmwatte/beets,sadatay/beets,Freso/beets,mathstuf/beets,Dishwishy/beets,moodboom/beets,kareemallen/beets,ttsda/beets,pkess/beets,multikatt/beets,artemutin/beets,lightwang1/beets,lightwang1/beets,ibmibmibm/beets,asteven/beets,xsteadfastx/beets,arabenjamin/beets,sadatay/beets,asteven/beets,tima/beets,mried/beets,ttsda/beets,SusannaMaria/beets,YetAnotherNerd/beets,Andypsamp/CODjunit,multikatt/beets,Wen777/beets,drm00/beets,imsparsh/beets,lengtche/beets,imsparsh/beets,kareemallen/beets,YetAnotherNerd/beets,jcoady9/beets,diego-plan9/beets,jcoady9/beets,Andypsamp/CODjunit,arabenjamin/beets,parapente/beets,jackwilsdon/beets,YetAnotherNerd/beets,imsparsh/beets,artemutin/beets,mathstuf/beets