This appears to have always been [-360 .. 360], as some tests in
test_shape_arc.cpp have had negative values for a very long time.
Add tests on the start, end and central angle accessors to enforce
the documented normalizations.
First, fix the error limit check in drc_test_provider_edge_clearance.
Then, we rotate the final point incorrectly in SHAPE_ARC::Collide (need
negative angle). We were not checking this result in the QA, so add the
proper tests
This means that you can run just a single case from the command line,
for example:
`qa_pcbnew -t DRCCopperSliver/_0`
The case is also automatically printed as context.
This means that when isolating a specific defect in one case,
you can run only that one case, which is useful under debuggers
and also when using slow tools like valgrind.
Not all possibe tests are doing this, but they're easy to do
when needed (i.e. when you want to run just one case)
Recommendation is to avoid using the year nomenclature as this
information is already encoded in the git repo. Avoids needing to
repeatly update.
Also updates AUTHORS.txt from current repo with contributor names
