UAV Outback challenge improvements from Team Swiss Fang

This is the collection of improvements done by the swiss team at the outback challenge. Needs validation / polishing.

@thomasgubler A merge with master would be great, I got confused by the (only two!) conflicts.
We have enough flash and its a good demonstrator for payload handling, so I'm tempted to leave it in. Would be nice if someone would be able to use it for the next Sparkfun ball drop competition.