osg::BuildShapeGeometryVisitor using GL_QUADS

[tomhog]

Some of the shapes built with osg::BuildShapeGeometryVisitor use GL_QUADS to draw their primitives. This isn't supported on GLES platforms so doesn't work out of the box.

The current solution is to use the osgUtil Optimizer with the osgUtil::Optimizer::TRISTRIP_GEOMETRY option to convert the GL_QUADS to tristrips.

[openscenegraph]

My plan is to have a look at this tomorrow (22nd March), should have a fix in my UK midday.

[openscenegraph]

I have now checked in changes the BuildShapeGeometry to replace GL_QUADS and GL_QUAD_STRIP with indexed GL_TRIANGLES: 48aa852