Improve/safety

- Adds a new delegate:

```objc
- (void)dataSource:(ANDYFetchedResultsTableDataSource *)dataSource
     didMoveObject:(NSManagedObject *)object
     withIndexPath:(NSIndexPath *)indexPath newIndexPath:(NSIndexPath *)newIndexPath;
```

- Support hidden controllers:
```objc
@property (nonatomic) BOOL parentControllerIsHidden;
```

> If the controller is hidden it reloads contents without animations

- Refreshes cell contents when they get moved.
Oh yeah, haven't thought about that.
So `return` is acceptable in the beginning of a method, as long as it is clearly visible within the method declaration? :)
That would make sense for me.