Get the SHA1 routines from git instead of openssl

..they are of a higher quality anyway, and this way we have one less
library to worry about.  And this way there is nobody who can claim that
openssl is not a system library and thus not compatible with the GPL.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Fix sha1 build for Windows

This works at least when cross compiling.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
Update the NSI installer script for Windows

This grabs the whole XSLT directory, adds osm-gps-map and removes the
OpenSSL dependency.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>