use a dictionary that subclasses can optionally extend to determine what nib to use
also use a dictionary for reuse identifiers
refactor controller
update cell factory dictionary methods
make classForFactory a property
cellFactory is now a public property of FODFormViewController
ability to initialize factory with a dictionary of cells and nibs
Merge pull request #2 from 1aurabrown/edit-controller

@orta -> update to cell factory, and changes to the view controller