Add example of an edit-dialog extension

[Nicklas Nordborg]

See ​http://base.thep.lu.se/ticket/1545

We should come up with some kind of simple example. One possibility is an extension that adds an any-to-any link with a file. This could be used to test ​http://base.thep.lu.se/ticket/1543 at the same time.

[Nicklas Nordborg]

(In [1269]) References #282: Add example of an edit-dialog extension

Adds a "Sample history file" tab to the "Edit sample" dialog. In the tab a user may select a file to link with the sample. It remains to implement an extension that saves the link.

[Nicklas Nordborg]

(In [1270]) References #282: Add example of an edit-dialog extension

Add the on-save part to the "Edit sample" dialog.

[Nicklas Nordborg]

(In [1271]) References #282: Add example of an edit-dialog extension

Add LastUpdatedBy extensions that automatically creates an any-to-any link between any item and the currently logged in user.

[Nicklas Nordborg]

(In [1272]) References #282: Add example of an edit-dialog extension

The LastUpdatedBy extensions can't create AnyToAny to non-BasicItem classes (eg. reporter) so print some debug info instead.

[Nicklas Nordborg]

(In [1273]) Fixes #282: Add example of an edit-dialog extension

Changed the "History file" extension to extend both the sample and extract edit dialogs to give an example of ​http://base.thep.lu.se/ticket/1554