Fix netmap acceptance tests

This commit:
  - Updates the netmap acceptance tests to have the correct identifying
    comment
  - Resets iptables inbetween the two tests since the rules can't be
    changed
  - Updates a regex in the iptables provider to check for spaces before
    and after a flag so that "--to" isn't confused with "--to-port"
Merge pull request #448 from cmurphy/fix_tests

Fix netmap acceptance tests