#52 Think about changing collection iteration/cursor scheme

[Dean Roddey]

The current collection cursoring/iterating scheme is a little bit non-intuitive. It might be worthing changing it such that it can use a for loop style iteration, instead of the do/while scheme used now.

It also might be worth getting rid of the internal collection iterator and providing non-const cursors as well, so that modifications to the collection element can be done via cursors instead of directly via the collection (because of the statefulness that implies.)