PROTON-543: document that Transport#sasl() must be called prior to any processing if a sasl layer is desired. Throw ISE from sasl() if process() has been called before the first sasl() invocation.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1607335 13f79535-47bb-0310-9956-ffa450edef68
PROTON-616: restrict keys for MessageAnnotations to be Symbols, update the transformers in contrib/proton-jms accordingly

Applied patch from Dejan Bosanac

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1607336 13f79535-47bb-0310-9956-ffa450edef68
PROTON-627: restrict keys for DeliveryAnnotations to be Symbols, update the transformers in contrib/proton-jms accordingly

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1607337 13f79535-47bb-0310-9956-ffa450edef68
PROTON-628: split out usage of the buffer in MessageImpl#decode() to its own method to enable supplying the buffer directly

Appled patch from Clebert Suconic with some indentation+whitespace fixup.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1607356 13f79535-47bb-0310-9956-ffa450edef68
debug statement (do not merge this)