Added an ignore list of emails to which we should not send any response. The main reason for this is that I got into an email loop with Mailer-Daemon and produced a zillion files in my tmp directory.

Fixed problem with event creation and permissions. Need to do refresh_perms on both underlying and overlying event.

Added model level permissions on Guardian.GroupObjectPermissions for members of the executives group. Also restored a modified version of the ModelBackend that *doesn't* do authentication. This is so that the has_perm check on Models can work.

Added changes to ligoauth.middleware.auth to allow user creation in the event that the user is not already found in the database. Applies to shib only.

Added context processor for login URL, added login URL to base template, added embedded discovery service page.

Conflicts:
	gracedb/api.py
	gracedb/views.py
	settings/branson.py