DALi C# binding - Generic Delegates support for EventHandlers

Implemented the Generic delegates to support EventHandlers for
all public classes.

Added a new cs file (manual/csharp/DaliEventHandler.cs) having declaration for
generic delegates.

Earlier usage of EventHandlers :
1) _application.Initialized += new Dali.AUIApplicationInitEventHandler(Initialize);
2) stage.Touched += new Dali.Stage.TouchEventHandler(OnStageTouched);
3) _scrollView.OnRelayoutEvent += new Dali.Actor.OnRelayoutEventHandler(OnScrollViewRelayout);

New usage of Generic EventHandlers:
ex:
1) _application.Initialized += Initialize;
2) stage.Touched += OnStageTouched;
3) _scrollView.OnRelayoutEvent += OnScrollViewRelayout;

Change-Id: I6ce2af12c825a9a7ef830049863dafb1f63e6a17
Signed-off-by: Ravi Nanjundappa <nravi.n@samsung.com>