Server Side solution for #310: Add Pull-to-Refresh Widget

The widget is named RefreshComposite and is basically a Composite. It
can do everything a Composite can do plus 2 additional features.

1) You can set a message that should be displayed when you pull down the
widget. The protocol property is called "message"

2) You can add RefreshListeners which will be notified when the user
pulls down the widget and let it snap back. The protocol event type is
called "Refresh" and has no properties. A respecting listen operation
will also be sent.

Change-Id: I4e6f37cbc82e649acdadde9afb2f8be01e292ff0
Server Side Solution for #317: Add spinning progress indicator

Change-Id: I6b5333e56f5670458d047e5df5be5fbad5e823d1
Merge "Server Side solution for #310: Add Pull-to-Refresh Widget"
Merge "Server Side Solution for #317: Add spinning progress indicator"