feat(live): progress on panel <-> data source communication patterns

public/app/core/core.ts

@@ -29,6 +29,7 @@ import {colorPicker} from './components/colorpicker';
 import {navbarDirective} from './components/navbar/navbar';
 import {arrayJoin} from './directives/array_join';
 import {liveSrv} from './live/live_srv';
+import {Emitter} from './utils/emitter';
 import {layoutSelector} from './components/layout_selector/layout_selector';
 import 'app/core/controllers/all';
 import 'app/core/services/all';
@@ -46,5 +47,6 @@ export {
   colorPicker,
   liveSrv,
   layoutSelector,
-  infoPopover
+  infoPopover,
+  Emitter
 };