major restructuring of rendering path.
more abstraction for scene rendering.
more math functions on points, vectors
adding very simple GL and Raytracing renderers.
slight change to scene rendering, plus simpler z buffer depth for rt.
use colortables (more) properly in scene renderers.
flesh out simple gl renderer.
re-enabling 1D plot support.
adding 1d plot bar plot styles.
enabling logarithmic again.
enabling logarithmic again
fixing header guard
re-enabling legend for 1d windows.
create real normals for normal-less triangle rendering instead of 0,0,1.
fixing node normals
don't resend plot geometry to renderer if it's not needed.
move main plot texturing into gl renderer.
fix caching of plots in scene renderers.
fixing virtual function for opengl plot caching
adding display list and vertex buffer options to gl rendering.
leaving them both disabled, since the old immediate mode is noticeably faster.