Localstorage adapter fixes:
• Don't call the success method with the entire model as argument
(backbone treats this as data returned from the server and SETS the
entire model to itself, creating a weird circular references)

• Don't save the entire backbone model stuff in localstorage, just save
the data.

• Use backbone's own internal mechanism for idAttributes. Not everyone
uses id

These fixes closes #190
Merge pull request #191 from karlwestin/localStorageFix

Fix for fullcalendar bug