Improve AttachentList

[timbl]

The attachmentList widget is used in several places (contacts, meetings, in editing profile for friends and communities), etc

The existing code tries to access the thing linked and make up a goof label for it. That works well sometimes, sometimes it fails (because of CORS etc). Te abiliy of the user to be able add an rdfs:label in the data would solve that problem.

Also may add a little comment on the link. "i found this invaluable" etc.

(In a separate issue, allow pressing on the target on mobile to copy from clipboard, for when you can't drag and drop)

also maybe add this to the foms