Jasmine categories

Adds support for categories to Jasmine, similar to [NUnit](http://www.nunit.org/index.php?p=category&r=2.6.2). To add a category to an existing suite or spec, provide the category name as an extra argument to the it, describe, or defineSuite functions.  E.g.:

```javascript
it('test description', function() {
    // code
    expect(result).toEqual(expected);
}, 'category');
```
To run the tests in a specific category, select the category from the drop down menu in the Jasmine runner or supply the category name as the `category` query parameter