Fix grunt karma

All unit tests should be passing now (checked only with PhantomJS and Firefox).

```bash
11:40:47 (fix-grunt-karma) ~/code/js/rxDataTable : grunt karma:full
Running "karma:full" (karma) task
PhantomJS 1.9.2 (Mac OS X): Executed 48 of 48 SUCCESS (3.061 secs / 0.204 secs)
Firefox 26.0.0 (Mac OS X 10.8): Executed 48 of 48 SUCCESS (4.216 secs / 0.197 secs)
TOTAL: 96 SUCCESS

Done, without errors.
```