Now that we support log line filtering (as of 0090c063) it's good to be
a bit more fussy about what log levels are assigned to different things.
Here we make a few things that are implementation details log as DEBUG,
and prevent spurious errors from EvalValidateCount where it was returning
an empty EvalValidateError rather than nil when everything was okay.
This is needed as preperation for adding WinRM support. There is still
one error in the tests which needs another look, but other than that it
seems like were now ready to start working on the WinRM part…
Martin Atkins