New module [ufw]: this module handles Ubuntu UFW operations

* Updated documentation related to IPv6 usage.

BugFixes:
* Solved the default_policy and state mutual exclusive status.
* Fixed changed status for IPv6 addresses.

Added @otnateos patch.
Add functionality and reduce complexity.

* Separate 'state', 'policy' and 'rule' commands
* Support for 'logging' command
* Support for 'direction' and 'interface' attributes
* Reliable change notifications based on 'ufw status verbose' diff