Ernieift/pico c

This adds a picoC widget to the gcs. Further more UAVObjects are available in user scripts. It also new is an access level management for writing sensible UAVObjects.
Here is a video of working: https://vimeo.com/100625857. Sorry for the poor quality, i try to upload it in HD soon.
Tested on OSX and Linux32-VM.
It is just worth emphasizing here, like I mentioned on IRC, this code will definitely allow users to upload picoC code that will lock the system into a flight mode they don't want and lose transmitter control. This makes picoC more powerful, but capable of causing problems.

I'm ok with this, but we should probably add appropriate warnings both on the wiki and gcs.