Integral Invariant curvature estimation

- Adding Integral Invariant curvature estimation on 2D / 3D shapes.
- Fix minor bug in ImplicitPolynomial3Shape & TrueLocalEstimatorOnPoints.
- Adding tools to compute eigenvectors / eigenvalues on matrix.
- Adding Decorators that allows you to make some unary operation (minus, add, intersection) on models of CDigitalBoundedShape and CDigitalOrientedShape for DigitalShapesDecorator and on models of CEuclideanBoundedShape and CEuclideanOrientedShape for EuclideanShapesDecorator.

Example :
@see testIntegralInvariantCurvatureEstimator2D.cpp testIntegralInvariantMeanCurvatureEstimator3D.cpp testIntegralInvariantGaussianCurvatureEstimator3D.cpp 
@see testEuclideanShapesDecorator.cpp testDigitalShapesDecorator.cpp