I noticed on our hosts some logrotate files named '*.1234.conf' --
these are coming from callers of logrotate role specifying
'/var/log/program/*.log', where the '*' is turning into a literal
filename. I didn't really consider this case.
Having a file-name starting with '*' may technically be fine, but is a
bad idea for everyone's sanity and it's potential to foot-gun some
sort of operation that suddenly wipes out a lot more than you wanted
to.
Let's just use the hash of the name to be unambiguous and still
idempotent. Make it more git-ish by using the same 7 digits as a
default short-hash.
Change-Id: I13d376f85a25a7b8c3a0bc0dcbabd916e8a9774a
1e2ea795c2