Hey,

it seems like your code has a major bug producing douplicates of valid lines of more than one filter is set:

     for (_j = 0; _j < opt.filters.length; _j++) {
        if (! lines[_i].match(opt.filters[_j])) {
            newLines.push(lines[_i]);
        }
      }

In the inner for loop you have to check if the line was already added or if better would be to add it in the first place and remove it if one of the filters match.
If you don't do this the line will be added for every filter that doesn't match.

Greetz

David