Added client system property "openejb.client.protocol.version" to allow new (4.6.x) OpenEJB clients to communicate with old (4.5.2) servers, with legacy test.

git-svn-id: https://svn.apache.org/repos/asf/tomee/tomee/trunk@1513095 13f79535-47bb-0310-9956-ffa450edef68