after refresh json data should be evaluated, otherwise it will be a string instead of an object
Cannot call method "getItem" of undefined when packing
Revert "Cannot call method "getItem" of undefined when packing"

This reverts commit 6b8752da787ba1879c27e11b068e5deafc8a209b.
Cannot call method getItem of undefined
Merge pull request #198 from DVSoftware/master

Added evalJSON during setup for `can.Model.Cached`