Feature/image view

This switch formatting looks a bit off, I don't think you wrote it, but still, it should look like this:

```ObjC
switch (format) {
    case FlickrPhotoFormatSquare:
        formatString = @"s";
        break;
    case FlickrPhotoFormatLarge:     
        formatString = @"b"; 
        break;
    case FlickrPhotoFormatOriginal:  
        formatString = @"o";
        break;
}
```