Fixes "CoreDataGeneratedAccessors" for ordered, to-many relationships. At the time of this writing, accessors are being auto-generated in the regular unordered KVC accessor pattern (NSSet-like), causing runtime crashes. Besides unrecognized selectors for most of the accessors, the following are common exceptions:

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSOrderedSet intersectsSet:]: set argument is not an NSSet'
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSSet isSubsetOfSet:]: set argument is not an NSSet'
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSOrderedSet isSubsetOfSet:]: set argument is not an NSSet'

The simplest use of this category is calling kc_generateOrderedSetAccessors when first initializing your model:

_managedObjectModel = [[NSManagedObjectModel alloc] initWithContentsOfURL:modelURL];
[_managedObjectModel kc_generateOrderedSetAccessors];

The fix generates the following methods on its entities's classes for each ordered relationship:

- (void)insertObject:(NSManagedObject *)value in<Key>AtIndex:(NSUInteger)idx;
- (void)removeObjectFrom<Key>AtIndex:(NSUInteger)idx;
- (void)insert<Key>:(NSArray *)value atIndexes:(NSIndexSet *)indexes;
- (void)remove<Key>AtIndexes:(NSIndexSet *)indexes;
- (void)replaceObjectIn<Key>AtIndex:(NSUInteger)idx withObject:(NSManagedObject *)value;
- (void)replace<Key>AtIndexes:(NSIndexSet *)indexes with<Key>:(NSArray *)values;
- (void)add<Key>Object:(NSManagedObject *)value;
- (void)remove<Key>Object:(NSManagedObject *)value;
- (void)add<Key>:(NSOrderedSet *)values;
- (void)remove<Key>:(NSOrderedSet *)values;

More fine-grained applications of these KVC methods are available through kc_generateOrderedSetAccessorsForEntity: and kc_generateOrderedSetAccessorsForRelationship:.

Calling the generated methods does not result in setting the underlying property with a new ordered set, as done by some other fixes for this issue. Instead, each method produces the appropriate KVO notifications for an ordered to-many relationship and uses the efficient dynamically-generated primitive accessors.

This category uses ARC. For use in a manual reference counting project, add the -fobjc-arc flag to "Compiler Flags" in Build Phases --> Compile Sources for NSManagedObjectModel+KCOrderedAccessorFix.m.