2d/Belyi_Torus: start normalizing hypermaps
2d/Belyi_Torus: canonical representant of isomorphism class
libvb/Toroidal: fix stupid float-vs-int bug
Merge branch 'toroidal_bug'
2d/Belyi_Torus: build list of existing triangulations
2d/Belyi_Torus: take number of vertices as argument
2d/Toroidal: one more abs vs fabs vs std::abs vs <cmath> bug