Add explicit dependencies for types

mysql_grant has an autorequire()'d dependency on the .my.cnf file used
by the provider to talk to the database.

I've added this to mysql_database and mysql_user too since logically
these also need the file to be in place.

I've hit this bug because of a slightly unusual edge case in our own
manifests, but I think this fix belongs upstream regardless.
Merge pull request #571 from jtopper/master

[MODULES-1333] Add explicit dependencies for mysql_database and mysql_user types