Integrate polymake source

[kenarab]

polymake is open source software for research in polyhedral geometry. It deals with polytopes, polyhedra and fans as well as simplicial complexes, matroids, graphs, tropical hypersurfaces, and other objects. Supported platforms include various flavors of Linux, FreeBSD and Mac OS.

It has a database included. We have to ask polymake developers if they want to curate a database of polymake generated polyhedra for including in Rpolyhedra.

At least the features must include to import and (maybe) export to polymake db format.