Rewrite part of -[TestAttributedStringHistory testUndo] that was failing on OS X 10.10 due to NSAttributedString differences.
Rewrite part of -[TestAttributedStringHistory testUndo] that was failing on OS X 10.10 due to NSAttributedString differences.

chris-armstrong/CoreObject,chris-armstrong/CoreObject,etoile/CoreObject,etoile/CoreObject,chris-armstrong/CoreObject,chris-armstrong/CoreObject,etoile/CoreObject,etoile/CoreObject