Merging to master branch: "Initial import of UFW module."

This reverts commit 7bfc60c9b8bac8ed00ca4bcc86d6571d7b73558d.
Features:
- Version updated to 2.1
- Added `name` option to allow use profile(s) located in /etc/ufw/applications.d
- More detailed description
- Added standard aliases like 'src', 'dst'
- Renamed `rule` option to `state`. Added `rule` as alias for `state`

Bug fixes:
- Return correct `changed` flag
Initial import of FreeBSD port module.
Fixed subprocess run and error return message.
Added reinstall option.
Be less verbose when successfully parsed make output.
Try to build port before uninstalling.
BugFix: iterate without override
Fixed a typo.
Added version_added
Merge branch 'patches'
* 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.
Merge branch 'ufw' into devel