new: gitfan.lib with Symmetry

to replace existing gitfan.lib once complete.

new features:
* new type permutation
* new type orthantFace
* new type orbitCone
* permutation(orthantFace) via permutation of unit vectors
* permutation(orbitCone) via transformation matrix

functions with examples suited for demonstration:
* orbitDecomposition // computes orbit decomposition of orthant faces
* afacesSymmetry // computes afaces with help of symmetry
* appendActionsOnOrbitSpace // computes transformation matrices of permutations