Added functionility to send new Ajax options from the <shouldRetry> meth...

Needed a way to update the timeout value within the shouldRetry method.  Decided to allow to return a boolean or object to the <done> method.  The object must contain a boolean called <willRetry> and any other ajax option properties that should be overridden.

I have not added any unit-tests to this fork but if you like the idea I can create some.