QPID-4546: delete links regardless of connection state.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1437187 13f79535-47bb-0310-9956-ffa450edef68
QPID-4546: review feedback and re-enable federation system tests

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1437188 13f79535-47bb-0310-9956-ffa450edef68