Ideas for Geometry improvements

[hamogu]

• rename Finite-Plane to box and or half box?
• add a triangulate method for boxes (essentially already existing in visualization.mayavi). They way, everything can be plotted as triangulation, which will make is easier to implement a minimal plotting backend, e.g. for vispay or direct OpenGL if Mayavi does not move to python 3 soon.
• move some stuff from apertures to geometry
  • make a generic geometry PlanewithHole that has outer_display, order_edge, inner_edge (or None), inner_edge_display (or None, only makes sense if inner_edge not None). This is for plotting.
  • Can this generalize the generate_local_xy? I don't think that's worth the effort.
• add triangulate method for Cylinders
• add triangulate method for torus
• rename classes that are now more general than their name (e.g. FlatGrating)
• test FlatGrating with a Cylinder shape

[hamogu]

Test of the FlatGRating with a patched shape shows the dangers of relying on dict (visualization) that's independent of the actual geometry that's plotted. That allows a shape that's different. In this case, I changed the center in pos4d for a Cylinder, but kept plotting "boxes" which directly uses the values in pos4d, not a function that the geometry supplies. Thus, it can be plotted, but won't show the cylinder. Need to think about how to controls these things more.