resources remove their panes in close()

src/atom/editor-pane.coffee

@@ -27,6 +27,9 @@ class EditorPane extends Pane
     el.addEventListener 'DOMNodeInsertedIntoDocument', => @resize()
     el.addEventListener 'DOMNodeRemovedFromDocument', => @resize()
 
+  remove: ->
+    @pane?.remove()
+
   resize: (timeout=1) ->
     setTimeout =>
       @ace.focus()

src/atom/resource.coffee

@@ -21,4 +21,5 @@ class Resource extends Pane
 
   close: ->
     atom.trigger 'resource:close', this
+    @pane?.remove()
     false