move unused media to trash too
move unused media to trash too

kenjhim/anki,subfusc/anki,ospalh/libanki3,sunclx/anki,eduOS/anki,weihautin/anki,holycrepe/anki,jakesyl/ruby-card,Arthaey/anki,hssm/anki,LucasCabello/anki,jkitching/anki,abeyer/anki,socialpercon/anki-1,xuewenfei/anki,go38/anki,florianjacob/anki,Stvad/anki,weihautin/anki,hssm/anki,jakesyl/ruby-card