PATCH: advapi32: updated shutdown functions

Created an attachment (id=8024)
Shutdown code updates

I have compiled it already and it seems to work so far. Initially, I was making changes to the shutdown program, but soon realized that in order to implement it would require functions that are unimplemented. Although the code (InitiateSystemShutdownExA/W) is nowhere near complete, I was able to streamline the functions InitiateSystemShutdownA/W by feeding them into InitiateSystemShutdownExA/W.

CHANGELOG:
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• Implemented the beginnings of InitiateShutdownA/W (nothing works yet).
• Running InitiateSystemShutdownA/W envokes InitiateSystemShutdownExA/W while using
  "Other (Planned)" as the reason code.

• The "Other (Planned)" reason code seemed to be the best default option so far.
  Let me know if you feel otherwise.

• Added the shutdown flags that are used for InitiateShutdownA/W inside of winreg.h.
• Include the reason.h header inside the winreg.h header so that the reason codes can be
  properly called. This conforms to the VC2010 method of adding this support.
• Added the declarations for InitiateSystemShutdownExA/W and InitiateShutdownA/W inside
  of winreg.h.
• In winuser.h, change the definitions for EWX_* to conform to MSDN documentation

• http://msdn.microsoft.com/en-us/library/windows/desktop/aa376868%28v=vs.85%29.aspx

• Added definition support for EWX_HYBRID_SHUTDOWN which is found in Windows 8.
• Calling InitiateSystemShutdownExA will convert strings to UNICODE and send it over to
  InitiateSystemShutdownExW. The same is also for InitiateShutdownA.