Default comment to name attribute

[dblessing]

By default, set the comment for a rule to the resource name. This enables simple rule creation with nice comments. Of course, if a user wants to they can still set an arbitrary resource name and specify a comment separately.

Instead of:

simple_iptables_rule 'some arbitrary thing' do
  comment 'accept all on loopback interface'
  chain 'INPUT'
  rule '--in-interface lo'
  jump 'ACCEPT'
  weight 1
end

We can now do this:

simple_iptables_rule 'accept all on loopback interface' do
  chain 'INPUT'
  rule '--in-interface lo'
  jump 'ACCEPT'
  weight 1
end

[rtkrruvinskiy]

@dblessing Thanks!