Resolve views that are referenced Ember CLI style.

Ember table currently has a hardcoded requirement that view classes be attached to a global objects, and so it's currently not possible to use it in Ember CLI projects which avoid them.

This patch adds Ember CLI style resolving while supporting the current global one. All these are valid now:
```javascript
tableCellViewClass: 'App.MessagePreviewView'  // Global Style
tableCellViewClass: 'message/preview'         // Ember CLI Style
tableCellViewClass: Ember.Table.TableCell.extend({ templateName: 'message/preview' })
```

Also, I've added alias' because I think it's more semantic to say:
```javascript
tableCellView: 'message/preview'
```