update to latest HEAD
- Check /usr for writability before running a transaction.
- Add repo= arguments to almost all RepoError raises, so we don't print unknown.
- Add/fix upgrade-minimal typos from man page.
- Replace vars in include lines in .repo files. BZ 977380.
- Make --setopt handle spaces properly. BZ 1094373
- Fix traceback when the history dir is empty. BZ 875610