The funky iteration here was at best annoying. Switch
it over to an iterator based approach with appropriate
BC code to simulate the old iteration style.
Depends-On: I19a8d6621a130811871dec9335038797627d9448
Change-Id: I9fccda15dd58a0dc35771d3b5cd7a6e8b02514a0
This is implemented in CirrusSearch so the result set can be looped
through multiple times. In general having a rewind function on any
iterator is probably a good idea, so pushing it into the upstream
interface.
Change-Id: Iaac9c11d8742288610011a2a0f6282944d35d5f3
