PROTON-302: added clear method to JNIDelivery

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1539393 13f79535-47bb-0310-9956-ffa450edef68
PROTON-448: Added support for Data encode/decode to Ruby Swig.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1539430 13f79535-47bb-0310-9956-ffa450edef68
PROTON-448: Added missed ChangeLog entry

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1539431 13f79535-47bb-0310-9956-ffa450edef68