made the expose_vec function generic and exposed additional vector types

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1027 fdac6126-5c0c-442c-9429-916003d36597
remove unnecessary include and typedef

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1028 fdac6126-5c0c-442c-9429-916003d36597
exposed missing vector functions

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1029 fdac6126-5c0c-442c-9429-916003d36597
exposed vec2 types

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1030 fdac6126-5c0c-442c-9429-916003d36597