oxford 700 800 improve com

the oxford controller doesn t acknowledge the cmds it receives, and sometime the controller just ignore some cmds.

The only way to know if the commands have been processed is to to check in the status packet (which is updated by a looping greenlet) that the concerned parameters have the expected values.

Unfortunatelly the controller pushes status packet data on the serial only each 1sec.

And sometime we have to wait the 2nd update to see that the concerned parameter has been updated.

Worse, if we want to see that a cmd has been ignored, we might have to wait the 3rd update to be sure that the parameter remains unchanged and therefore detect that the sent cmd was ignored.

This issue will try to:

• provide methods to check if a cmd has been received and processed
• retry the cmd if it was ignored
• have an option (in cmds that set something) to block until it has been processed for real.