Remove git-status-changed event from Buffer

This is now fired as a status-changed event from
the Git class when the checkout completes normally
and the status of the path changes.

src/app/buffer.coffee

@@ -422,8 +422,7 @@ class Buffer
   checkoutHead: ->
     path = @getPath()
     return unless path
-    if git?.checkoutHead(path)
-      @trigger 'git-status-changed'
+    git?.checkoutHead(path)
 
   scheduleStoppedChangingEvent: ->
     clearTimeout(@stoppedChangingTimeout) if @stoppedChangingTimeout

src/app/git.coffee

@@ -114,7 +114,9 @@ class Git
     return head
 
   checkoutHead: (path) ->
-    @getRepo().checkoutHead(@relativize(path))
+    headCheckedOut = @getRepo().checkoutHead(@relativize(path))
+    @getPathStatus(path) if headCheckedOut
+    headCheckedOut
 
   getDiffStats: (path) ->
     @getRepo().getDiffStats(@relativize(path)) ? added: 0, deleted: 0

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

@@ -46,7 +46,6 @@ class StatusBarView extends View
     @buffer?.off '.status-bar'
     @buffer = @editor.getBuffer()
     @buffer.on 'contents-modified.status-bar', (e) => @updateBufferHasModifiedText(e.differsFromDisk)
-    @buffer.on 'git-status-changed.status-bar', => @updateStatusBar()
     @updateStatusBar()
 
   updateStatusBar: ->

src/packages/status-bar/spec/status-bar-spec.coffee

@@ -153,14 +153,13 @@ describe "StatusBar", ->
       rootView.open(newPath)
       expect(statusBar.gitStatusIcon).toHaveClass('new-status-icon')
 
-    it "updates when a git-status-changed event occurs", ->
+    it "updates when a status-changed event occurs", ->
       fs.write(path, "i've changed for the worse")
       git.getPathStatus(path)
       rootView.open(path)
       expect(statusBar.gitStatusIcon).toHaveClass('modified-status-icon')
       fs.write(path, originalPathText)
       git.getPathStatus(path)
-      rootView.getActiveEditor().getBuffer().trigger 'git-status-changed'
       expect(statusBar.gitStatusIcon).not.toHaveClass('modified-status-icon')
 
     it "displays the diff stat for modified files", ->

src/packages/tabs/lib/tab.coffee

@@ -13,7 +13,6 @@ class Tab extends View
     @subscribe @buffer, 'path-changed', => @updateFileName()
     @subscribe @buffer, 'contents-modified', => @updateModifiedStatus()
     @subscribe @buffer, 'saved', => @updateModifiedStatus()
-    @subscribe @buffer, 'git-status-changed', => @updateModifiedStatus()
     @subscribe @editor, 'editor:edit-session-added', => @updateFileName()
     @subscribe @editor, 'editor:edit-session-removed', => @updateFileName()
     @updateFileName()