Fix and improve auto_update

This now pulls the repo if the user has gotten the Auto-patcher from our
download page. Should still be an option for cygwin/ApG users w/o modification
to ApG, although testing is necessary.

Fixed some updating coming from branch "auto-update" instead of master

Improved network testing, output and logging.
Add changelog.txt

I may end up printing this at the end of the script too...idk yet.
versioning to 2.9.855