Convert all interface specifications to just Specification.

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/branches/CONNECTORS-946@1601557 13f79535-47bb-0310-9956-ffa450edef68
Fix for CONNECTORS-960.  Remove usage of Specification subclass from connector interfaces.

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/trunk@1601560 13f79535-47bb-0310-9956-ffa450edef68