- ortho grid now draws scaled by the view3d 'Scale' setting, venomgfx noticed this was missing.
- so as not to confuse add scale next to unit display text, so rather then "Metres" it shows "Metres x 1.5" otherwise its confusing that grid lines are not in exact units.
- changed grid spacing to grid scale (needed for more logical behavior with units)
- when units are enabled grey out subdivisions.