Added chkconfig headers to mysql.init initscript. Refs #2350

Now chkconfig is aware of mysql.init script and does not exit with
error anymore.

Removed config db defaults, to set mysql.init disabled.
New nethserver-mysql-init action. Refs #2350

The nethserver-mysql-init action is compatible with and replaces
"mysql.init" initscript. It loads any *.sql or runs any executable
file from /etc/e-smith/sql/init.
Spool directory in /var/spool/nethserver-mysql-init. Refs #2350

Adhere to FHS:
http://www.pathname.com/fhs/pub/fhs-2.3.html#VARSPOOLAPPLICATIONSPOOLDATA