PROTON-192: reinstate public constructors in proton-j but deprecate them, as agreed on the mailing list

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/branches/jni-binding@1440005 13f79535-47bb-0310-9956-ffa450edef68
PROTON-194: WIP pulled up README files (not finished), tidied up cmake files (eg now including proton.py in proton-j-impl.jar), and renamed maven profile to proton-jni.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/branches/jni-binding@1440006 13f79535-47bb-0310-9956-ffa450edef68
PROTON-194: WIP moved python tests to shallower location for convenience of C developers; general pom.xml tidying up

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/branches/jni-binding@1440007 13f79535-47bb-0310-9956-ffa450edef68