Add interface and isolation directories, with hierarchy

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/branches/CONNECTORS-957@1600756 13f79535-47bb-0310-9956-ffa450edef68
Update connector-build to include more isolation support

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/branches/CONNECTORS-957@1600762 13f79535-47bb-0310-9956-ffa450edef68