Fixed clang warning

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1185 fdac6126-5c0c-442c-9429-916003d36597
Signed unsigned warning

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1186 fdac6126-5c0c-442c-9429-916003d36597
Updated changelog

git-svn-id: http://openmesh.org/svnrepo/OpenMesh@1187 fdac6126-5c0c-442c-9429-916003d36597