Don't count expected errors towards numberOfErrorsToReport limit

[JonasAlaif]

Linked to viperproject/silver#583

[mschwerhoff]

I like concise PRs :-)

[JonasAlaif]

@mschwerhoff It seems that errorsReportedSoFar doesn't get reset between test runs, and so causes the refutation tests to fail. We should reset this number to 0 between tests; ideally somewhere here. Any idea how I can get access to the errorsReportedSoFar val from there?

[mschwerhoff]

Not your fault, of course, but Verifier is not a StatefulComponent and should not have state that needs to be reset. BaseVerifier would probably be a better fit. Resetting should then happen in def reset().