[#141] Support dialog without buttons
[#140] Make Accept, Reject and Cancel method as protected
[#138] Support Closed event for DialogVm
Adapting to SL: AppStarter
Move MessageBox methods to common class part
Create and return cell from category if not exists
Use factory default identifier instead Guid.Empty
[#131] Autorelease application if it was not initialized before InvokeApp
Adaptation for SL: GenomeAssemblyController
Adaptation for SL: Extract color standart dialog