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
apply bootstrap styling to menutree block modify template
formatting
format and validate markup
update helplink plugin for new module types
correct typo
conver to bootstrap tabs
improve sentence
had height definition to modal window
revert styling to old zikula.ui type for modal window
allow non-standard bracketurls beginning with `ext:` to pass thru un-processed
rename menutree api
accomodate bootstrap style menutrees