[COOK 3974] Template out debian.cnf file before issuing restart

MySQL will otherwise be unable to restart because the `debian-sys-maint` user will have the incorrect password on disk.

Also refs COOK-4001
[COOK 4001] only create /etc/init/mysql.conf on the ubuntu platform

The template - `init-mysql.conf.erb` - does not exist in the templates directory for debian, and therefore this fails to install on debian systems. The mysql package provides an init file, so it is not necessary for those systems.
[COOK 3974] Move ubuntu-12 init-mysql.conf.erb template to default specificity

The template is required on ubuntu systems and need only be overriden by ubuntu-10. Thus, it makes most sense to move it to default specificity, rather than override for each ubuntu version forever.

Refs:

- COOK-3974
- COOK-3945
- COOK-3931
- COOK-4001

PRs:

- opscode-cookbooks/mysql#128
- opscode-cookbooks/mysql#132
- opscode-cookbooks/mysql#137
- opscode-cookbooks/mysql#144

Affected systems:

- Non-LTS Ubuntu
- Debian-based systems