AJTOOLS-4 Data field not being parsed properly by WireShark plugin if two or more AllJoyn Messages are combined in single TCP packet.

Fixed bugs where multiple messages are combined in a single packet.
Fixed bugs where a single message is distributed across multiple packets.
Fixed bug where arrays of zero length were not dissected properly.

Change-Id: Icfb83e73519d8217d6c477edf531ba6d3f3dcd48
Reviewed-on: https://code.wireshark.org/review/4159
Tested-by: Petri Dish Buildbot <buildbot-no-reply@wireshark.org>
Reviewed-by: Michael Mann <mmann78@netscape.net>