Merge pull request #876 from spicyj/cb-ctx

Always call callback in component context

src/core/ReactMount.js

@@ -318,7 +318,7 @@ var ReactMount = {
       container,
       shouldReuseMarkup
     );
-    callback && callback();
+    callback && callback.call(component);
     return component;
   },
 

src/core/ReactUpdates.js

@@ -102,7 +102,7 @@ function enqueueUpdate(component, callback) {
 
   if (!batchingStrategy.isBatchingUpdates) {
     component.performUpdateIfNecessary();
-    callback && callback();
+    callback && callback.call(component);
     return;
   }