Fix readme to match current cookbook logic

Doesn't expect the rule template name to start with `port_` anymore.
COOK-1883 : Adding a requirement for perl since /usr/sbin/rebuild-iptables is a perl script
Merge pull request #2 from gene1wood/master

COOK-1883 : Cookbook iptables has unstated perl requirement
release v0.11.0
Add a disabled recipe for convenience
Merge pull request #3 from eedgar/COOK-2213

Add a disabled recipe for convenience
release v0.12.0
Merge pull request #1 from matschaffer/patch-1

Fix readme to match current cookbook logic
Merge branch 'master' of github.com:opscode-cookbooks/iptables