Replace most calls to open by a new wrapper.
* common/sysutils.c (any8bitchar) [W32]: New. (gnupg_open): New. Replace most calls to open by this. * common/iobuf.c (any8bitchar) [W32]: New. (direct_open) [W32]: Use CreateFileW if needed.
This is yet another step for full Unicode support on Windows.
- GnuPG-bug-id: T5098