Add transitions to splash screen and main menu
Add a new Box2D bodies factory

This factory is being used now in all samples to reduce the amount
of code.
New Box2D sample

This sample show how to use sensors but maybe is too easy. We'll have to
do another one about this.
Replace SensorsSample with CollisionsSample

This sample show how to detect collisions between objects.
Remove not used field
Reduce transition duration by 1/4 seconds

Splash image movement has been also reduced to show the menu sooner.
Refactor Box2DFactory

Now three calls are necessary to create a body but would be easier for
the final user to understand the code.
Add a new collision condition

When the ball touch the box the screen turns blue.
Refactor samples to use new Box2DFactory
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