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.
I don't know why, but I can't seem to set the environment variables inside
git-annex to work around the git error caused by android's crappy username
and hostname settings. This workaround works, and that's all that's good
about it.
Git fails on Android, because it gets some weird domain for local host like
"localhost.(none)". This works around that. I made it always set EMAIL when
GECOS workaround was needed (unless EMAIL is already set). It might be
nicer to try to get the hostname.domain as git does, and only set it if
that fails. But I don't want to be stuck trying to exactly duplicate
whatever git is doing.