Added flushChain method
Added IPv6 handling
Customized serveral interfaces to allow passing of extra parameters
Fixed bug in getReferringRules method, it was resolving rule index incorrectly
Fixed bug in constructor, iptables-save is an executable, but "iptables-save -c" is not an executable
Changed calls to iptables-* to optionally use sudo
Added debug flags plus statements
Merge pull request #1 from jkldv/master

Bug fixes, IPv6, flushChain, sudo