Change int to size_t to fix compiler warnings
Protect against attempt to dump and zeroed-out message, and a add timestamp to message debug info.
AllJoyn-2268: Clear message after consuming it so that only reply is sent. Added checks to handle cleared message structure. While in the code took opportunity to map some AJ_Printf() calls to use the new debug APIs.
AllJoyn-2269:  When looking up an msgId checkr return an error status if the object is currently disabled.