Column sort order buttons do not work on Safari iOS (BB-16103)

Newly-added column sorting headers do not work on iOS Safari

Steps to reproduce:

1. view your list of repositories using iOS Safari
2. click on Last Updated header (sort last updated)
3. click on Repository header (sort alpha)
4. note order of repositories

Actual result:

Order does not change. Order remains alphabetical.

Expected result:

Order should change to the expected order as per the header title

Additional notes:

Tested on iOS 8.4 and iOS 6.1 Safari. Both have the problem.

The up/down caret also does not change in the headers when you tap them.