Offer the user to secure his mysql setup

From https://wiki.ubuntu.com/MythTVTeam/TODO

1. Ask the user if they want to secure mysql if they do not have a root password. Warn about security issues!

3. Ask the user if the system is to be a standalone PVR or part of a MythTV network and configure bind-address in my.cnf accordingly

Discussion in #ubuntu-mythtv

< superm1> there is a debconf stub in mysql-server-5.0 for it already
< superm1> so it should be pretty straightforward

Probably involving shared templates... we'll see.