yepher/CoreDataUtility — pull request #37 by jpage4500 (2014-11-12 16:31:06+00:00)
Title: several fixes for sorting by column

- fix column sorting including:
> nil objects are sorted above non-nil objects
> NSDate column sorting will compare NSDate objects directly
> NSNumber column sorting compares NSNumber objects directly
> NSSet/NSArray/NSData objects are sorted according to their size (count or length)
> no need to create NSString objects anymore for non-string column types