Turn URLs in the commit message to actual html links

[jnikula]

We have plenty of URLs in References/Bugzilla/Link/etc tags in the commit messages. Would be nice to have those turned into actual html links. Whether it's better to do this as a regexp on http[s] on all of the commit message, or just for some specific tags, I'll leave at the discrecion of the implementer.

This is a low-prio wishlist item, obviously.