Impl. a new algorithm for checking if a point is within a triangle and removed old sources for this task.

refactor rotation functions to seprate functions to compute a rotation matrix and a function to rotate points with a given rotation matrix

For this reason the reworked class template Vector3 is used.

The template arguments are matrix type and vector type. For new
matrix types it is necessary to specialize the template. This is
done for DenseMatrix as matrix type and double* as vector type.