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
* Update documentation
* Cleanup
Add protocol options 'esp' and 'ah'.
Fix typo: 'reseted' -> 'reset'.
Insert rule to a specific num.
Recognize rule changes even if ufw is in disabled state.

See http://askubuntu.com/questions/30781/see-configured-rules-even-when-inactive
for the details.
Merge pull request #5518 from pyykkis/ufw

UFW module (another take)