[Win8] Protocol to reactivate suspended game
The protocol can be used to reactivate a suspended game, therefore we should only create the game object if it does not already exist.
Add DebuggerHidden attribute to CheckGLError
The DebuggerHidden attribute makes the debugger break at the caller of CheckGLError if an exception is thrown, not inside CheckGLError.  This is much more helpful to devs as they do not have to manually navigate up the callstack.
Merge pull request #1723 from slygamer/win8-protocol

[Win8] Protocol to reactivate suspended game
Fix using statement.
Merge pull request #1730 from slygamer/debuggerhidden

Add DebuggerHidden attribute to CheckGLError
Merge branch 'develop' into develop.Core
Added PCL targets and installation instructions
Merge pull request #1732 from DDReaper/develop.Core

Added the PCL targets and installation instructions