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.
Look at the parent class, you only need to implement the class members you plan to use or the ones you are obliged by the interface (the pure virtual members). This particular member has a parent implementation and you are not doing anything with it here so you can just delete it and the parent implementation will be used instead.