InvenioConnector: fix for CDS authentication

* CFG_CDS_URL uses 'https' instead of 'http' when logging
  in (necessary since commit 9ecb1748).

* Looks for "Sign in" link instead of "login".

* Updated for new Single Sign-on page.

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
Merge branch 'maint-1.1'

* maint-1.1:
  InvenioConnector: fix for CDS authentication

Conflicts:
	modules/miscutil/lib/invenio_connector.py