I hate buoyancy so much
Add sensor property to fixture definitions
Move original BuoyancySample code to another file
Fix all bugs (I hope so) in PolygonUtils methods
Add a new BuoyancySample class and a buoyancy controller

The controller needs refactoring and small fixes.
Change code to spawn boxes every time the screen is touched
Fix BuoyancyController. At least is better now...
Buoyancy working as expected now. Source refactoring needed yet
Apply small refactoring
Small changes previous to new version
Add LICENSE file. We use MIT license now
Change code version to 0.5.0