Immediately fetch new buffers' git status in GitRepository

We used to emit buffer added events before the buffers were loaded, so we
would end up fetching their git status soon afterwords, when they emitted
the did-reload event.

src/git-repository.coffee

@@ -437,6 +437,7 @@ class GitRepository
       if bufferPath = buffer.getPath()
         @getPathStatus(bufferPath)
 
+    getBufferPathStatus()
     bufferSubscriptions = new CompositeDisposable
     bufferSubscriptions.add buffer.onDidSave(getBufferPathStatus)
     bufferSubscriptions.add buffer.onDidReload(getBufferPathStatus)