A whole bunch of changes to get the layout to work on mobile, i18n, etc.

* Change the layout so that the entire form area gets the scroll bar for languages that use a lot of text or if the user has a lot of email addresses.
* Change the way the privacy policy and buttons are rendered so JS is not needed to set the width of the privacy policy.
* Put the TOS on its own line.
* Put "Always sign in using this email" on its own line
* Change the order of the "Forgot your password?" button and "password" label so that Germanic languages render the entire thing on one line.
* Remove the "Sign in using" header text.

issue #1300
issue #1286
issue #1275
issue #1274
issue #1272
issue #1262
issue #1261