Firewall: standardize usage on ufw module

Standardize all UFW manipulations from [ufw module](http://docs.ansible.com/ufw_module.html) from Ansible extras. Remove duplicate UFW setup from logging and swift-proxy roles.

Resolves #578.
Since the task details changed, should the name reflect that it's not just ipv4 (or just take out the IPV4 part of the task name)?