Add method to get ahead/behind commit counts

src/app/git.coffee

@@ -138,5 +138,8 @@ class Git
       directoryStatus |= status if path.indexOf(directoryPath) is 0
     directoryStatus
 
+  getAheadBehindCounts: ->
+    @getRepo().getAheadBehindCounts()
+
 _.extend Git.prototype, Subscriber
 _.extend Git.prototype, EventEmitter

src/stdlib/git-repository.coffee

@@ -17,3 +17,4 @@ class GitRepository
   isSubmodule: $git.isSubmodule
   refreshIndex: $git.refreshIndex
   destroy: $git.destroy
+  getAheadBehindCounts: $git.getAheadBehindCounts