Made it possible to hide the email adress field during registration for external auth modules, refs #1330, #900, #901. Note: The user still could edit the email adress via the browsers console and validating the email adress is still required.
Bootstrapped login, added icon option to login providers, partially converted to jQuery, closes #1230, refs #1214.
Merge pull request #1389 from cmfcmf/auth-refactoring-2

Authentication refactoring