PROTON-662: decoder.c pn_decoder_decode_value has a test that won't correctly execute.

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1622873 13f79535-47bb-0310-9956-ffa450edef68
PROTON-663: codec.c pni_inspect_atom uses the wrong format for case PN_CHAR

git-svn-id: https://svn.apache.org/repos/asf/qpid/proton/trunk@1622875 13f79535-47bb-0310-9956-ffa450edef68