Wordnet is missing some words.

I feel like this is a bug, but Im still digging in.

wordnet.lookup('fought', function(results) {
    // no results. 
}

http://wordnetweb.princeton.edu/perl/webwn?s=fought&sub=Search+WordNet&o2=&o0=1&o8=1&o1=1&o7=&o5=&o9=&o6=&o3=&o4=&h=

Related to #225 CC: @morungos