some changes
	modified:   eZLib/nbproject/project.properties
	modified:   eZLib/src/eZLib/Physics/Friction.java
	modified:   eZLib/src/eZLib/Sketch.java
	modified:   eZLib/src/eZLib/Study/BouncingBall.java
	modified:   eZLib/src/eZLib/Study/FrictionSketch.java
	modified:   eZLib/src/eZLib/Vector.java