Display parent-child group hierarchy in group drop-down and checkbox widgets

We've implemented hierarchical display of groups in Manage Groups listing (CRM-10635) - but not yet for other places where we show a list of groups:

• Basic and Advanced Search
• Edit Contact > Groups pane
• Groups tab under view contact

We need a method that returns permissioned groups in a hierarchical sort:

A Parent
A Child of A Parent
B Child of A Parent
B Parent
C Parent
A Child of C Parent

etc.