partially fix #637 NSMakeRange in rangeOfAnchorNamed:

This request fixes wrong using NSMakeRange macros in  rangeOfAnchorNamed: method.

Unfortunatelly  similar correction of NSMakeRange in _rangeOfObject:inArrayBehindAttribute:atIndex: method will broke unit test testEmptyListItemWithSubList. So I leave NSMakeRange in _rangeOfObject:inArrayBehindAttribute:atIndex: untouched.