Also modify the linkage of kiface objects, as this is not
supported by older CMake versions.
This was accidentally removed with the reversion of the application
of the wrong patch (8f11a2133).
QA: fix object files
Devolve the logic as to whether a pad should be numbered or not
to a pad utility function. Add a very simplistic test for this
function (demonstrating how to test BOARD_ITEMs in general).
Fixes: lp:1804787
* https://bugs.launchpad.net/kicad/+bug/1804787