Support views row field value delta

It is quite common that a gallery has something like a "main image".

Supporting the delta on a field output (instead of outputting all) would allow this feature. (identical for all images)
If you want this feature per-image (choose the main image separately), you'll need to use a separate image field or a separate nodereference field for the image-node approach. An improved UI would be very helpful.

Referring to
#1185248: Better options page and per-page options