Don't wrap callback functions which need to return value to fullcalendar...

According to http://arshaw.com/fullcalendar/docs1/mouse/eventClick/ and http://arshaw.com/fullcalendar/docs1/event_data/eventDataTransform/ , after fullcalendar calls `eventClick` and `eventDataTransform`, it will then consume the return value.

If we wrap those two callbacks with `wrapFunctionWithScopeApply`, the wrapper function calls the wrapped function with `$timeout` and never pass the return value back to fullcalendar.

This breaks the design of these callbacks.

To fix this issue, the patch just avoid to wrap `eventClick` and `eventDataTransform`. I just did a quick scan of the documents and only find these two. There might be more callbacks toe ignore.

This PR fixed #122