if id.watch() is called in the head, and document.body
doesn't exist yet, a listener is added for domready, and then
the iframe is created.

stores loggedInUser into a local variable, and notifies
the Channel whenever it finally builds

fixes #2252

* Use termsOfService over tosURL and privacyPolicy over privacyURL
* Check for renamed/deprecated tosURL and privacyURL.
* Check for deprecated requiredEmail.
* Check for renamed loggedInUser/loggedInEmail

* Add the notion of momentos to the state machine so that back properly works.

* Use termsOfService over tosURL and privacyPolicy over privacyURL
* Check for renamed/deprecated tosURL and privacyURL.
* Check for deprecated requiredEmail.
* Check for renamed loggedInUser/loggedInEmail

* Show a console.log message that silent has been deprecated.
* Bring over some helper functions from PR #2228 to check for deprecated options, print console messages.

Fix "IE doesn't keep you logged in between restarts (or page reloads)" problems by disabling cookie check in iframe.  issue #2218 & issue #2183

Fix "IE doesn't keep you logged in between restarts (or page reloads)" problems by disabling cookie check in iframe.  issue #2218 & issue #2183

Fix the user going back to the "enter email" state if they select an email using auto-complete and then type CTRL-C on the email address.

in clear(), after calling localStorage.removeItem, call setDefaultValues to ensure the dialog has a set of values for each of its fields whenever the verification page loads.

* Move the "passwords do not match" on the set password screen above the first password.
* Move the "this email address and password do not match" above the email field.

removeListener throws in IE8

only Firefox seems to make the placeholder text
be the same color as the normal text, so this will
set the placeholder to a lighter grey

fixes #2187

* sites_signed_in => number_sites_signed_in
* sites_visited => number_sites_remembered

* Disable the email field.
* Focus the first password field instead of the email field.
* If no email is stored (user did not come from /signin or /signup), redirect the user to /signin.
* If email address that is stored is not known, redirect to /signup.
* If email address that is stored is known but a primary, redirect to /signin
* When calling User.addressInfo on a primary address, check whether the address is known or not.  Allows us to simplify the forgot page.