PROTON-301: modify test infrastructure to allow valgrind tests of SSL

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1476228 13f79535-47bb-0310-9956-ffa450edef68
PROTON-301: fix error introduced in common.py

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1476377 13f79535-47bb-0310-9956-ffa450edef68