images in form

[marcin-filipiak]

We should make it possible to display graphics on the form. Graphics sent in a new "field" called "image" in "members" section of JSON.
Image encoded with base64.

{ "type": "image", "name": "smile", "value": "image/jpeg;base64,/9j/4AAQSkZJRgABAQEBLAEsAAD//gATQ3JlYXRlZCB3aXRoIEdJTVD" }