This adds a test program which can be used to test the
parsing of a given KiCad PCB file. This interface is
useful for both manual or automated debugging of given
files, as well as providing an interface suitable for
fuzz-testing tools.
Also adds to the testing docs to detail how fuzzing can
be used.
Also moves some useful re-usable code from io-benchmark
to a new library qa_utils, which can contain code that
isn't need in the actual KiCad libs.
John Beard