Went through even more of the tutorial

Box2D_v2.2.1/Testbed/Tests/Tutorial/Ball4.h
Box2D_v2.2.1/Testbed/Tests/Tutorial/CollisionFilterTest.h
  - Finished [Collision filtering]
Box2D_v2.2.1/Testbed/Tests/Tutorial/SensorContactListener.h
Box2D_v2.2.1/Testbed/Tests/Tutorial/SensorTut.h
  - Finished [Sensors]
Box2D_v2.2.1/Testbed/Tests/Tutorial/RayCastTut.h
  - Finished [Ray casting]
Merge branch 'master' of https://github.com/dnunez02/sfml-project