Added Thrustmaster DirectConnect with Attack Throttle support.

[dferyance]

This is support for the Thrustmaster DirectConnect protocol. The only joystick I have that uses it is the Attack Throttle so it is currently specific to this device. The throttle has an analog port that it captures and transmit with it's digital data. This analog port handing is written assuming rudder pedals and a thrustmaster joystick is used although both are optional and other analog joysticks will work.

DirectConnect, like the other digital protocols can chain devices but my understanding it is via splitters and not daisy chained. I have no support for this as I only have one joystick to test with.

[necroware]

Thank you very much for the contribution. I will try to make a code review in the next days. I'm very grateful for every such contribution, so if I'll have some suggestions, please see them as notes for me in the first place. So I know, if some refinement hast to be done, before it gets integrated. The Arduino is very timing sensitive and I found that it can be broken even by unrelated code. That's why I have to double check everything before the integration.

[necroware]

Thank you very much once again for the contribution! This looks already very promising, but still needs some work. If you have not time I can do the fixes, but I'll definitely will need your help for testing and adjustments....

[necroware]

A support for this joystick and potentially for all other TMDC compatible models was added in #108
That PR was tested with another joystick, but it would be nice to give it a try also with Attack Throttle. If there are some bits missing we could try to improve that with the bits from this PR.