'or' was not gettext() decorated in index.ejs - allow a translator more control over the whole phrase

gettextify the last portion of the about page.

Cachify the logo as well.

issue #1999

extensive testing of i18n mechanism - including english fallback, string substition from .json files, and debug locale

issue #1167

rename the 'add email' email we send out to 'confirm', and use it in both the email addition case, and the email reverification case.  This is more about semantics than behavior change

Generalize error-display to extended-info.  For every "screen" that is shown, create an extendedInfo and instantiate it.  Remove the "error-display.show" code that was in page_helpers and page_module.

issue #1916

issue #1938

issue #1941

issue #1871
issue #1937

* Add a new module called dom-helpers with function makeEqualWidth.
* Force buttons on the "Is this your computer" screen to be the same width.
* Update CSS enable button width to be set this way.
* Update CSS to vertically center helper text.
* Update CSS to make the buttons look good in mobile.

issue #1932

issue #1925

Change the placeholder for the verification password from "Repeat Password" to "Verify Password" to match the dialog.

issue #1923

issue #1895

Make the options passsed to the check_registration controller more explicit.  Uncollapse the signIn divs in dialog.ejs  Fix string extraction.

fixes #1861

fixes #1851

common/
      js
      css
      i

dialog/
      js
      css
      i

pages/
      js
      css
      i

* Create common .submit > p and .tospp CSS declarations.

issue #1733

* Make the about code use a PageModule.
* Include the about module in the static_resources instead of including it separately.
* Start the about module when looking at the about page.
* Add ultra basic unit test for about page.

* Only show info once the account has been verified.
* Unify the styles for the "has this address already been registered" error.
* Remove all the dead code that was left over from issue #1000 merge.

issue #1734

Change browserid.org urls to persona.org, introduce static.login.persona.org for all static resources.