Backup/Restore profiles

[costales]

Change the Import/Export for Backup/Restore?
Reason: #1410839

The backup/restore could be a nice feature to have a way back if the user does something wrong.
If he presses restore (import) he could find the standard profiles, wich Gufw had at first run , in the backup folder.
Gufw would be able to make automated backups, too.

If the user clicks "backup" button he gets a message like this
"A backup of your Office.profile has bes saved to /etc/gufw/backup/Office_(Time and Date here).profile"
"Do you want to open the backup folder in your file browser now ? yes/NO"
And if he clicks "YES" , the file browser (nautilus) opens with user rigths leading him to the fixed path /etc/gufw/backup/ where he can copy and paste his backups to an other path if he wants.

PROS:
1. Automated backups.
2. No injection paths.
3. Easy.
CONS:
1. The users will ask about come back the import/export.
2. It's more complicate restore a backup between machines (in local machine it could be Backup/Restore and show just the backup profiles). Yes, I know is easy, but for some users not.
3. I'd prefer not to open Nautilus, it will be a root window.