Trigger 'grammars-loaded' when TextMate packages finish loading

This is a temporary solution so we can merge async textmate package
loading. I'd like to dispense with this event and consider each
grammar individually as they are loaded. But this makes the behavior
compatible with the old background-task-based behavior.

src/app/text-mate-package.coffee

@@ -12,6 +12,12 @@ class TextMatePackage extends Package
   @testName: (packageName) ->
     /(\.|_|-)tmbundle$/.test(packageName)
 
+  @getLoadQueue: ->
+    return @loadQueue if @loadQueue
+    @loadQueue = async.queue (pack, done) -> pack.loadGrammars(done)
+    @loadQueue.drain = -> syntax.trigger 'grammars-loaded'
+    @loadQueue
+
   constructor: ->
     super
     @preferencesPath = fsUtils.join(@path, "Preferences")
@@ -22,7 +28,7 @@ class TextMatePackage extends Package
     if sync
       @loadGrammarsSync()
     else
-      @loadGrammars()
+      TextMatePackage.getLoadQueue().push(this)
     @loadScopedProperties()
 
   legalGrammarExtensions: ['plist', 'tmLanguage', 'tmlanguage', 'cson', 'json']
@@ -38,6 +44,7 @@ class TextMatePackage extends Package
     TextMateGrammar.load path, (err, grammar) =>
       return console.log("Error loading grammar at path '#{path}':", err.stack ? err) if err
       @addGrammar(grammar)
+      done()
 
   loadGrammarsSync: ->
     for path in fsUtils.list(@syntaxesPath, @legalGrammarExtensions) ? []