Absolute URLs for links appearing in feed

note that this changes the oft-used byline()
Issue 1859: Challenge settings don't catch contradictory dates
Issue 1859: Challenge settings don't catch contradictory dates
Stashing change
Issue 1841: Added cucumber test
simplified
simplified
simplified
simplified
simplified
simplified
simplified
simplified
simplified
simplified
simplified
Issue 2662: Deleting Tag Set without javascript
Issue 2662: Cannot delete tag sets with JS disabled
Issue 2663: Tag sets: Can't Delete nominations without JS
Issue 2661: Tag sets: Can't Clear Nominations without JS