Clear GrammarRegistry in AtomEnvironment::reset

src/atom-environment.coffee

@@ -246,6 +246,8 @@ class AtomEnvironment extends Model
     @commands.clear()
     @registerDefaultCommands()
 
+    @grammars.clear()
+
     @styles.restoreSnapshot(params?.stylesSnapshot ? [])
 
     @menu.clear()

src/grammar-registry.coffee

@@ -123,6 +123,3 @@ class GrammarRegistry extends FirstMate.GrammarRegistry
   clearGrammarOverrides: ->
     @grammarOverridesByPath = {}
     undefined
-
-  clearObservers: ->
-    @emitter = new Emitter