NO-JIRA: added pom comments

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1489373 13f79535-47bb-0310-9956-ffa450edef68
NO-JIRA: make logging and exception messages more useful.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1489489 13f79535-47bb-0310-9956-ffa450edef68