Mixed Native and Managed Debugging Improvements for Windows Store Apps

Introduced improvements to mixed native and managed debugging for Windows Store apps in Visual Studio 2012 Update 1. This includes enabling mixed mode debugging via project properties, enhancing object inspection in locals/watch windows for WinRT objects, applying Debugger Type Visualizers, and enabling remote debugging on x86/x64 machines. Execution control improvements allow for more reliable stepping between WinRT and native components.