Compliance with Apache License 2.0

[MartinSpiessl]

I read up a bit about the Apache License 2.0 and found out that it requires at point 4 b):

You must cause any modified files to carry prominent notices stating that you changed the files;

As we sometimes need to fix tasks, we would either have to put such a notice or ask the original author to agree upon the new version without such a notice.

So are we strictly speaking currently violating the Apache License 2.0 in those instances I described or is there a loop hole I am not aware of?

Shouldn't we then default to 3-clause BSD instead, which does not to my knowledge have such a clause?

[PhilippWendler]

After #1099, we can add SPDX-FileCopyrightText: 2011-2020 The SV-Benchmarks community to all such files. This is the common strategy to handle this requirement (example 1, example 2).