Added a new DemoRunner project to the solution. This can help to write little proof-of-concept like demos to CodeSharper.
CodeSharper.DemoRunner:
  - New project for testing and demoing
CodeSharper/Todos/codesharper.todo:
  - Added new to do item.
Updating DemoRunner application
CodeSharper/CodeSharper.DemoRunner/MainWindow:
 - Add a new view for demos
CodeSharper.DemoRunner/Common/DemoAttribute:
 - Add a new attribute type for representing demo applications
CodeSharper.DemoRunner/ViewModels/MainWindowViewModel:
 - Add a new view model for main window
CodeSharper.DemoRunner/ViewModels/ViewModelBase:
 - Add an abstract class of view models
Add a new REPL (Read-Eval-Print loop) demo to demo applications.
CodeSharper/CodeSharper.DemoRunner/Common/ConsoleHelper:
 - Add a console helper class that can open console window from WPF
CodeSharper.DemoRunner/DemoApplications/IDemoApplication:
 - Add a standard interface for running demo applications