That's needed in files used to build the configure program.
For the other files, I'm keeping my __WINDOWS__ define, as I find that much easier to type.
I may search and replace it to use the mingw32_HOST_OS thing later.
Both the directory and webdav special remotes used to have to buffer
the whole file contents before it could be decrypted, as they read
from chunks. Now the chunks are streamed through gpg with no buffering.