Add constants.
* include/winbase.h [_WIN32_WINNT >= 0x0501] (ACTCTX[AW]): Add
structures.
* include/winbase.h [_WIN32_WINNT >= 0x0501] (ActivateActCtx): Add
function. MSDN says the first argument is HACTCTX but I'm not sure
where such a specialized handle is defined, so use HANDLE instead.
* include/winbase.h [_WIN32_WINNT >= 0x0501] (AttachConsole,
CheckNameLegalDOS8Dot3[AW]): Add functions.
* lib/user32.def (ActivateActCtx, AttachConsole,
CheckNameLegalDOS8Dot3[AW]): Add functions.
* lib/user32.def (AddLocalAlternateComputerName[AW]): Add functions.
Unfortunately I don't know which header to put the declarations in.