msi: Do not crash in MsiGetUserInfo if org, user or serial are not present, instead return USERINFOSTATE_ABSENT.

to be able to make use of FileStructW and avoid W->A->W roundtrips if
possible.

Based on a patch by Aric Stewart.
Also get rid of _ILCreateFromFindDataA and _ILCreateFromPatA.

Add _ILIsUnicode as a simple pidl test.

Implement _ILGetTextPointerW, though it does little now.
Handle the LPWSTR from _ILGetTextPointerW in _ILSimpleGetText and
_ILSimpleGetTextW.

msi: Register fonts with full target paths as applications can and will install fonts to places other than the windows/fonts directory.

This avoids server round-trips for all file I/O.

Allows moving the FD_FLAG_OVERLAPPED support to the generic
get_handle_fd request handling.