backups: repo-local hg configuration
originally, this solved #232 (closed) in a future-proof way by backuping everything but the store. But that includes several binary files that may turn out to be risky (although it's the norm in Mercurial world for files to be platform independent, for shared filesystems use cases).
Now it's just a minimal fix for #232 (closed), the caches will have to be rewarmed at restore time.
Edited by Georges Racinet