PROTON-420: added error.h portion of patch

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1552221 13f79535-47bb-0310-9956-ffa450edef68
added released status

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1552223 13f79535-47bb-0310-9956-ffa450edef68