Remove dispose buffer observer when editor is closed. Check that the editor is the active one to not cause problems when multiple editors are pointing to the same buffer.
Remove dispose buffer observer when editor is closed. Check that the editor is the active one to not cause problems when multiple editors are pointing to the same buffer.

rylanc/atom-react,orktes/atom-react,MiincGu/atom-react,extrabacon/atom-react,nickhudkins/atom-react,Nihu98/atom-react,AdshadLib/atom-react,gre/atom-react,jeffshaver/atom-react,blurrah/atom-react