More correctly and automatically support running the role as a user other than root

I use a special sudo user to run ansible, rather than a root user.  Since Ansible modules like *mysql_user* read credentials from `$HOME/.my.cnf` but the role tasks could be in sudo mode, the modules are always trying to read from `/root/.my.cnf` regardless of the actual ansible user or `mysql_user_home` rolevar.  This works great when you happen to be using the root user anyway, but otherwise, problems.

This hopes to address that.