Ardrone to master

Hello paparazzi developers,

We (mavlab) want to merge the ardrone2 development back into master. First I'm going to explain some background information so it's clear what the context is and what has been done so far.

We began with two groups each working on getting paparazzi on an ardrone. The difference is that one group went with the pure/raw approach. That means writing drivers for actuators, sensors and other hardware. The second team went with the SDK/API approach. On the ardrone2 runs a software program which provides an API trough AT-Commands which can be used to communicate what you want the ardrone to do. So the second team does not directly control the ardrone, but tells the middleware software what to do.

Now there two branches were called minor1 (raw) and minor2 (sdk). Later on I branched of minor1 my own branch called dhensen. Last week I've merged dhensen + minor2 into ardrone_to_master with some help from C. de Wagter.

With the sdk version we can allready fly autonomously with an u-blox gps receiver.
With the api version we need some more tuning and maybe ultrasound + barometer.

Now we want to merge it back into master as soon as possible, because a lot of acadamic work is depending on it.

TODO for SDK version:
-cameras (from sdk/api, should be relatively simple)
-gains tuning

TODO for RAW version:
-solve magnetometer problems
-read out battery (i2c?)
-ultrasound integration/implementation
-baro calculations
-cameras (reverse engineered)
-gains tuning

TODO for both versions:
-gps module integration

I'll be waiting for the pull request to be accepted! In the mean time feedback is very much welcome and will be handled with care.

-Dino