rp info'izing many modules.

* Update the state machine to use rpInfo instead of its own state
* Move rpInfo related pick_email logic to pick_email from state.
* Push rpInfo out to authenticate. Remove additional unneeded tests from the state_machine.
* check_registration module gets rpInfo instead of siteName only.
* Convert verify_primary_user.js to use the RpInfo model.

Additionally:
* When signing a user in, set the logged_in flag from the generate_assertion module.
* Remove functionality from user.js that has been moved to rp_info.js
* Get rid of the requiredEmail tests in check_registration.
RpInfo-ize the communication_iframe & cleanup

* in rp_info.js, if a siteName is not specified, return the hostname for getSiteName()
* The RP origin on the main site is https://login.persona.org
* Include rp_info.js everywhere.
* Add new tests for ops that perform calculations
* Fix JSHint errors.
* Ensure the tests run.
* add models.js before interaction_data.js in the communication_iframe
Merge pull request #3940 from mozilla/extract-rp-info

Extract rp info