FreeBSD Migration to Git

FreeBSD doc and src repositories have migrated from Subversion to Git.

While SVN revision IDs have been preserved, and links to these revisions should continue to work, branches are somewhat confused (git doesn’t actually directly track what branch a commit was made on, you have to painstakingly infer it) and tags are currently missing.

I’m working to resolve these issues, which will also help with other git-using projects such as DragonFlyBSD.