Remove redundant _ADDRESS postfix.
Remove unnecessary Mac#to_a.
Updated TODO list.
Rewrite arp/request_spec.rb using rspec_given.
Merge branch 'feature/refactor_arp_request' into feature/refactor_arp

Conflicts:
	pio.org_archive
Rewrite arp/reply_spec.rb using rspec_given.
Updated TODO list.
Refactor Arp::Request.
Refactor Arp::Reply.
Refactoring.
Refactor Arp classes.
Merge pull request #24 from trema/feature/refactor_arp

Feature/refactor arp