Remove the axis numbering code from ARRAY_OPTIONS
and place in a new class, ARRAY_AXIS. This keeps
the logic for the array item numbering separate from
the logic for the array item geometry.
This simplifies the logic in the ARRAY_OPTIONS class, which
no longer has to deal with the numbering of each axis.
The geometry and numbering logic is separate to the dialog, and
can be separated for clearer logic and better testability.
Moreover, refactor it to avoid any dependency on pcbnew
classes, so it can be move to common for potential re-use in
eeschema and friends in future.
Also convert all wxPoint logic in these classes to VECTOR2I and
fix some function visibilities.
Add some unit tests of the ARRAY_OPTIONS geometry and numbering.
John Beard