Use change event instead of buffer-change event

This will update the modified indicator after operations
are undone

spec/app/status-bar-spec.coffee

@@ -55,18 +55,26 @@ describe "StatusBar", ->
 
   describe "when the buffer content has changed from the content on disk", ->
     it "disables the buffer modified indicator on save", ->
+      expect(statusBar.bufferModified.text()).toBe ''
       editor.insertText("\n")
+      expect(statusBar.bufferModified.text()).toBe '*'
       editor.save()
       expect(statusBar.bufferModified.text()).toBe ''
-      editor.backspace()
-      editor.save()
 
     it "disables the buffer modified indicator if the content matches again", ->
+      expect(statusBar.bufferModified.text()).toBe ''
       editor.insertText("\n")
       expect(statusBar.bufferModified.text()).toBe '*'
       editor.backspace()
       expect(statusBar.bufferModified.text()).toBe ''
 
+    it "disables the buffer modified indicator when the change is undone", ->
+      expect(statusBar.bufferModified.text()).toBe ''
+      editor.insertText("\n")
+      expect(statusBar.bufferModified.text()).toBe '*'
+      editor.undo()
+      expect(statusBar.bufferModified.text()).toBe ''
+
   describe "when the associated editor's cursor position changes", ->
     it "updates the cursor position in the status bar", ->
       editor.setCursorScreenPosition([1, 2])

src/app/buffer.coffee

@@ -192,7 +192,6 @@ class Buffer
     oldRange = Range.fromObject(oldRange)
     operation = new BufferChangeOperation({buffer: this, oldRange, newText})
     range = @pushOperation(operation)
-    @trigger 'buffer-change'
     range
 
   clipPosition: (position) ->
@@ -241,7 +240,6 @@ class Buffer
     @setPath(path)
     @contentOnDisk = @getText()
     @trigger 'after-save'
-    @trigger 'buffer-change'
 
   isInConflict: ->
     @isModified() and @isModifiedOnDisk()

src/app/status-bar.coffee

@@ -30,7 +30,8 @@ class StatusBar extends View
     @editor.on 'cursor-move', => @updateCursorPositionText()
 
     @updateBufferModifiedText()
-    @editor.getBuffer().on 'buffer-change', => @updateBufferModifiedText()
+    @editor.getBuffer().on 'change', => @updateBufferModifiedText()
+    @editor.getBuffer().on 'after-save', => @updateBufferModifiedText()
 
   updateBufferModifiedText: ->
     buffer = @editor.getBuffer()