ReaderWriterSynchronized: adding warning when no custom attribute on method.
Upgraded to latest PostSharp.
SimpleContactManager: added undo/redo.
SimpleContactManager: added more logic.
Merge branch 'initial'

Conflicts:
	SimpleContactManager/ContactControl.xaml.cs
	SimpleContactManager/Entities/Contact.cs
	SimpleContactManager/Entities/DatabaseMock.cs
	SimpleContactManager/MainWindow.xaml
	SimpleContactManager/SimpleContactManager.csproj