Enforce stricter requirements for Editor.getPane()

Previously it would return the closest '.pane' element
which would cause an editor inside of another editor
to report having a pane such as in the autocomplete view.

src/app/editor.coffee

@@ -639,19 +639,19 @@ class Editor extends View
     @requestDisplayUpdate()
 
   splitLeft: (items...) ->
-    @pane()?.splitLeft(items...).activeView
+    @getPane()?.splitLeft(items...).activeView
 
   splitRight: (items...) ->
-    @pane()?.splitRight(items...).activeView
+    @getPane()?.splitRight(items...).activeView
 
   splitUp: (items...) ->
-    @pane()?.splitUp(items...).activeView
+    @getPane()?.splitUp(items...).activeView
 
   splitDown: (items...) ->
-    @pane()?.splitDown(items...).activeView
+    @getPane()?.splitDown(items...).activeView
 
-  pane: ->
-    @closest('.pane').view()
+  getPane: ->
+    @parent('.item-views').parent('.pane').view()
 
   remove: (selector, keepData) ->
     return super if keepData or @removed

src/packages/bracket-matcher/lib/bracket-matcher.coffee

@@ -41,7 +41,7 @@ module.exports =
 
   goToMatchingPair: (editor) ->
     return unless @pairHighlighted
-    return unless underlayer = editor.pane()?.find('.underlayer')
+    return unless underlayer = editor.getPane()?.find('.underlayer')
 
     position = editor.getCursorBufferPosition()
     previousPosition = position.translate([0, -1])
@@ -127,7 +127,7 @@ module.exports =
     startPairPosition
 
   updateMatch: (editor) ->
-    return unless underlayer = editor.pane()?.find('.underlayer')
+    return unless underlayer = editor.getPane()?.find('.underlayer')
 
     @hideHighlightViews(editor) if @pairHighlighted
     @pairHighlighted = false

src/packages/status-bar/lib/status-bar-view.coffee

@@ -9,7 +9,7 @@ class StatusBarView extends View
       @appendToEditorPane(rootView, editor) if editor.attached
 
   @appendToEditorPane: (rootView, editor) ->
-    if pane = editor.pane()
+    if pane = editor.getPane()
       pane.append(new StatusBarView(rootView, editor))
 
   @content: ->