Allow adding of cssClass to ResourceView

It would be really useful to be able to colour the resource columns.  This small change would allow us to use:

```javascript
resources: [
    {
      name: 'Resource 1',
      id: 1,
      cssName: 'mycssclass'
    },
    ...
  ],
```

If there is no cssClass set, jQuery will not add any class so this will not affect existing code.