Rename MNSTableViewSection to be more general
Refactor table view controller logic into view hosting and object-backing classes
Add collection view support
Demonstrate collection view support

Lay out the numbers with a flow layout, and use a compact presentation
of prime flags for use after each prime number.
Rename to MNSDataMediator
Support reloading mediated data in table and collection view controllers
Fix insets bug in collection view controller
Support toggling showing prime flags in number collection view
Simplify demo number table and collection view controllers
Support selecting objects in collection view
Change object count in demo view controllers
Fix wording in comments