- decimater (incremental & mc) doesn't require normals anymore

- mod normalFlipping & normalDeviation computes normals, if mesh hasn't normals
- add 2 decimater unittest (decimating with normalFlipping and initialize all modules)

git-svn-id: http://www.openmesh.org/svnrepo/OpenMesh/trunk@1049 fdac6126-5c0c-442c-9429-916003d36597

src/OpenMesh/Tools/Decimater/ModNormalDeviationT.hh

@@ -108,12 +108,22 @@ public:
   {
     set_normal_deviation(_max_dev);
     mesh_.add_property(normal_cones_);
+
+    const bool mesh_has_normals = _mesh.has_face_normals();
+    _mesh.request_face_normals();
+
+    if (!mesh_has_normals)
+    {
+      std::cerr << "Mesh has no face normals. Compute them automatically." << std::endl;
+      _mesh.update_face_normals();
+    }
   }
 
 
   /// Destructor
   ~ModNormalDeviationT() {
     mesh_.remove_property(normal_cones_);
+    mesh_.release_face_normals();
   }