Changed Atom::Content to use a Delegate(String) super class instead of SimpleDelegator.  Gives a bit over an order of magnitude better performance when handling atom content.
Changed Atom::Content to use a Delegate(String) super class instead of SimpleDelegator.  Gives a bit over an order of magnitude better performance when handling atom content.

git-svn-id: 3ba875d7fc4f0ecc98b007236c8de30a33efad96@2717 f9e11ea3-fe04-0410-b62f-af45e3a9b5a1

instructure/ratom,seangeo/ratom