exposed additional mesh functions (accessing and deleting items, number of elements, connectivity)

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1019 fdac6126-5c0c-442c-9429-916003d36597
added two more circulator unit tests

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1020 fdac6126-5c0c-442c-9429-916003d36597
Fix for c++11 call to pointer to member function of type 'VertexIter ()' drops 'const' qualifier (Thanks to Ronald Richter and Kenshi Takayama for the fix)

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1021 fdac6126-5c0c-442c-9429-916003d36597