node 0.9.1, reporters second param config error

## example code

`
var reporter = require('nodeunit').reporters.html;
reporter.run(path, secondparam);
`
- the 'secondparam' must config testSpec and testFullSpec , otherwise lead to a undefined error, but not all the reporters have the bug nodeunit version 0.9.1;

Start at the HTML reporter entry point shown in the example, reporter.run(path, secondparam), and compare how its second parameter is handled with the other reporters. Reproduce the undefined error using nodeunit 0.9.1 and verify that configurations containing testSpec and testFullSpec work without breaking reporters that do not have the issue.

索引モデルが issue の本文から書いたものです。