The basic problem is that the DRC engine does length testing and skew
testing by collecting all the diff pair constituent parts and pairing them
itself. Since each part is collected on its own, we need to ignore the
'B' unit when evaluating any conditional expressions. However, doing this
in general means that when evaluating "OwnClearance()" we also ignore the
'B' unit and return the diff pair CLEARANCE_CONSTRAINT when we shouldn't.
This implements a more discerning test which know what the current requested
constraint is when evaluating expressions.
See also https://forum.kicad.info/t/solved-custom-differencing-rule-not-working-drc/34034/6
Fixes https://gitlab.com/kicad/code/kicad/issues/11314
(cherry picked from commit f7cdc7af75)
in most of files, including wx.h is not necessary, when only 2 or 3 wx files must be included.
Moreover, on windows, including wx.h sometimes create compil warnings about
shadowed vars defined in some specific windows headers.
The use of printf, wxLogDebug, and std::err/std::out causes excessive
debugging output which makes finding specific debugging messages more
difficult than it needs to be.
There is still some debugging output in test code that really needs to
be moved into a unit test.
Add debugging output section to the coding policy regarding debugging
output.