These aperture macros were previously used but only for chamfered round rect.
They are now also used for custom pads (previously drawn as regions).
They are also optimized, i.e. only one aperture macro is created for a given shape.
(previously, one aperture macro was created for each chamfered round rect pad.)
So now all pads are flashed.
plotter.h contains now only a header common to all plotters.
The code does not actually change, but it allows modifying a specific plotter
without recompiling most of kicad files.
jean-pierre charras