PROTON-2149: session state is a property, not a method
PROTON-2149: session state is a property, not a method

This closes #216.

astitcher/qpid-proton,ChugR/qpid-proton,apache/qpid-proton,apache/qpid-proton,apache/qpid-proton,ssorj/qpid-proton,gemmellr/qpid-proton,apache/qpid-proton,ssorj/qpid-proton,ChugR/qpid-proton,ChugR/qpid-proton,astitcher/qpid-proton,ssorj/qpid-proton,astitcher/qpid-proton,kgiusti/qpid-proton,astitcher/qpid-proton,ssorj/qpid-proton,ChugR/qpid-proton,apache/qpid-proton,kgiusti/qpid-proton,gemmellr/qpid-proton,gemmellr/qpid-proton,kgiusti/qpid-proton,apache/qpid-proton,ssorj/qpid-proton,gemmellr/qpid-proton,kgiusti/qpid-proton,ChugR/qpid-proton,kgiusti/qpid-proton,ChugR/qpid-proton,ssorj/qpid-proton,gemmellr/qpid-proton,gemmellr/qpid-proton,astitcher/qpid-proton,kgiusti/qpid-proton,astitcher/qpid-proton