Avoid innecesary firewall restart

[javier.amor.garcia@…]

Firewall is always restarted when saving modules changes. In my computer that means about 3 seconds that not are always neccesary.

Possible plan:

• make a changed sub in GConfModule (default: looks into the gconf key)
• make nmodIsChanged use the previous sub (for speed concerns those two points may be optional in almost all modules via a gconf key)
• make a sub firewallChanged in Firewall::Observer (defualt return true)
• make sure all firewall using modules inherit from FireWall::Observer
• make firewall use this sub to determine if it has to restart
• change Global saveAllModules and modIsChanged to use this feature

[juruen@…]

Executing all the iptables commands with just one sudo command makes much faster.