Basic feature set, unit tests, and README

@Raizlabs/maintainers-ios 
Basic features implemented for RZAutoImport. I welcome all feedback as well as code review from anyone who is interested. For the sake of transparency, my plan is to extend this category as a replacement for RZDataImporter, with eventual CoreData extensions to replace most if not all of the functionality of RZDataManager in a cleaner, more understandable, well-documented way.