I posted the MAVLink test tool to github at GitHub - bclay1297/MavTest: Windows /Visual Studio version of the mavlink c_uart_interface_example
It now recognizes all of the message in the Common and Development tree. There are other messages listed but I have not found the headers for them so I conditionally compile those out for the time being.
The tool can send a few messages as listed in the readme file on github. As far as I can tell the outgoing messages have the same format as output from QGroundControl but for some reason my drone does not change its state. I do not get a COMMAND_ACK when I send a COMMAND_LONG message. I have not found any prerequisites list for sending messages.
Windows users please download the code and test with your drones to see if it s a drone specific issue