adding all jwt supported fields

-added support for all currently supported JWT parameters, including custom user fields
-includes @jbdietrich's UTF-8 fixes (https://github.com/zendesk/zendesk_jwt_sso_examples/pull/15)

NOTE: many changes (including bumping the aspJSON version) take place in the zipped bundle

-cleaned up formatting per @morten 

@steved555 @jcheatham @jbdietrich