Merge pull request #2724 from edx/will/studio-xblock-save

Native XBlock Studio Save UI

common/static/coffee/src/xblock/runtime.v1.coffee

@@ -2,4 +2,13 @@ class XBlock.Runtime.v1
   children: (block) => $(block).prop('xblock_children')
   childMap: (block, childName) =>
     for child in @children(block)
-        return child if child.name == childName
+        return child if child.name == childName
+
+  # Notify the client-side runtime that an event has occurred.
+  # This allows the runtime to update the UI in a consistent way
+  # for different XBlocks.
+  # `name` is an arbitrary string (for example, "save")
+  # `data` is an object (for example, {state: 'starting'})
+  # The default implementation is a no-op.
+  # WARNING: This is an interim solution and not officially supported!
+  notify: (name, data) -> undefined