Bug 215 - contextual menu bits

This commit originally dates from 01 Aug 2012. I had to redo the jQuery
portion of the patch to pick up new syntax, but everything else applied
normally and should be considered tested against the code of that era.

The easiest way to make the links appear in the hover menu, for testing
purposes, is to "return 1" at the top of can_receive_vgifts_from in User.pm.