Add patron's photo at registry process

We would want to be able to use photos that exist on another server so academic libraries could just add links to a student's image when student records are loaded.

As a consortium with both public and academic member libraries, we would want to be able to control this feature at the systems level. Some academics might want this to be required and other libraries may want this to optional or not use it at all.

The photo_url column is in actor.usr, and the image tag is already in display_overlay.xul. The only puzzle piece missing is the method to store the images and link the user to the image. An org_unit_setting could provide a default path per OU. If the images were named with the actor.id, and stored in the appropriate path, it would be very simple to implement. Although the image management would still be left to an outside mechanism.

In Elizabeth's case, if the photo_url column were populated during the student record load, they would just magically appear. Depending on image size, some style may be needed for proper display.

While some libraries may need to make patron photos mandatory, many public libraries may wish to have the patron elect not to provide a photo. So you would have at least 3 possibilities:

1) Library does not choose option of photo id
2) Library chooses option of photo id but not required for registration
3) Library chooses option of photo id and is required for registration.

Adding a note that photos added via the photo_url field are not displaying in the web client. I submitted bug 1697716 to track this issue.

I added the needsdiscussion tag, because it seems like we should get some end-user consensus to guide us through this wide variety of use cases.

Noting re forthcoming discussion that bug 1697716 was fixed a while back and images-via-photo_url now do display in the web client.