Add rc.local to backup (+ list of other files?)

[jrierab]

When generating a backup file, the /etc/rc.local file should also be included. This should be easy

Also, it would be wonderful, but maybe not that easy, if it included also:

• * A list of user-installed packages (even if they should then be recovered manually).
  * User-made scripts present in /sbin

Maybe it could be easier to include a config file with the paths to extra files to add to the backup settings file. Let's say some /etc/config/backup_me file.

This would very much help when updating FW on very customized setups.