MOD_NOREPEAT is a constant that is used by the RegisterHotKey function, as seen here: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646309(v=vs.85).aspx
MOD_NOREPEAT should be contained in winuser.h. The attached patch adds it to the winuser.h header.
I didn't accept the attached patch but added an appropriate implementation for MOD_NOREPEAT pending release of 4.1.