refactor session store initializer
set the path attribute of the session cookie when a relative url root is set
config can contain an empty string. use presence to convert that to nil. pass it directly to :path. rails handles the nil case with its default like before.
disable async jobs in test env by default
remove superfluous disabling of async jobs
manipulating asynchronicity with Delayed::Worker.delay_jobs should work by now
little comment improvement
Merge pull request #1133 from opf/feature/sync_delayed_jobs_in_test_env

disable async jobs in test env by default
Begin to replace OpenID with omniauth

Only UI yet is a link on the dedicated login page, a lot of OpenID remains are still in there and things are absolutely not secure or nice.
Omniauth: Allow correcting validation errors via registration form

This also sets User#password_change_allowed? to false for users
authenticated via Omniauth and thus hides login and passwords fields
from the register form when using Omniauth.
Omniauth: Hide authentication fields for users with external source

This removes identity_url from safe_attributes and permitted_params
and prevents admins from setting it as we are using identity_url now
to identify users with an external authentication provider.
Refactor UsersController#update a little
Omniauth: Fix lost_password deciding whether to allow reset
redirect to first_login page for all new users to set accessibility mode
Replace of flash notice for registration scenarios with automatic login
AccountController: Rename method
add omniauth failure callback and specs for omniauth login/registration
bugfix for register method and refactoring of specs

  Bugfix register method was missing user.save for exteranl
  authentication other than omniauth.

  Refactoring of omniauth specs to use let method to set omniauth
  hash.
Removal of unnecessary auth_hash method
Small refactoring of omniauth specs