added a function for creating faces from python lists of vertex handles

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1077 fdac6126-5c0c-442c-9429-916003d36597
moved connectivity functions into their own file

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1078 fdac6126-5c0c-442c-9429-916003d36597