Support for config acks and multiconfig options (for the cool stuff)

[bkw]

I wrote a gist on why we need to do something about client.config() and what my current plan of attack is here: https://gist.github.com/4416785

Maybe this should go into the new api? It's really time I had a look at it.

[felixge]

Had a look at the gist - LGTM!

About new api: Huh, I guess somebody needs to go ahead and finish this. I think we also need a comparability mode for the old api if we push this. Not sure if I will find the time right away. How much hacking time do you have atm @bkw ? : )

[bkw]

Not much at the moment. There might be more time in February though.

[wiseman]

I think this would help with #74 too. It seems that to update ephemeris you need to do a client.config('gps:ephemeris_uploaded','RESET', 1) and make sure it's been sent and processed before starting the FTP transfer--without an ACK I think the only alternative is to wait some amount of time and hope it went through.

Once the FTP is done, you need to send another gps:ephemeris_uploaded config to tell the drone to process the ephemeris. My guess is that you want to send that config once and only once, which an ACK would also help with.

I played a little with AT*CTRL to control ACKing, but didn't get it working the way I expected. Does anyone else have the start of code to handle this?

[wiseman]

Looks like maybe ROS has a complete config implementation: AutonomyLab/ardrone_autonomy#26