WinDX Support For Left/Right Control, Shift, and Alt Keys

We had to switch over to using WK_KEYUP/DOWN events to properly capture the control, shift, and alt keys.

I'm unsure about suppressing the system menu here, but it does allow the alt key to be captured.

UPDATED:

This now uses RawInput to capture keyboard events.  Also I tested XNA4 on the desktop.... it also suppresses the system menu.