Improves how invalid primitives are handled
Improves how invalid primitives are handled

- Warn only the first time that a geometry has invalid primitives
- Discard only invalid primitives from geometry, if there is valid primitives
they will be displayed.

cedricpinson/osgjs,jtorresfabra/osgjs,cedricpinson/osgjs,jtorresfabra/osgjs,cedricpinson/osgjs,jtorresfabra/osgjs