core: added support for signing up with facebook for a known user.
Moved some check functions to m_identity.
Fixed problem where an email identity could be added multiple times (when signing up using FB)
(cherry picked from commit bb0e7fa4ff6f97ff630dc113cbb58c450c67ee12)
Fix for close button on persistent notices.
(cherry picked from commit e93467c5ecb73b4420480163928febd1ea0331e6)