Update SplineArea.java

Changes to the area algorithm, changes to be made
Update SplineLength.java
Working cubic
Merge branch 'master' of https://github.com/zypus/CAD
Update CubicSpline.java

almost..
Merge branch 'master' of https://github.com/zypus/CAD
Working cubic spline.
Merge branch 'master' into fabian

Conflicts:
	src/splines/CubicSpline.java