Consider splitting errors into fatal/error/warning/info

[tobez]

Requested by Daniel Stirnimann:

Nonetheless, I think in the long term it could still make sense to
provide the granularity of different error levels such as ERROR, WARNING
and maybe INFO. For example: you have a buggy signer which leaves some
old RRSIGs by accident and your zone is not in an algorithm key rollover
state as described above. The operator has enabled the above new policy
check because some of his zones do have an algorithm key rollover at one
point in time. Without providing different error levels, the operator
will not detect this failure in the buggy signer.
Maybe you could just log such situations in the "verbose" output so that
an operator has the chance to detect them. Current verbose logging would
be marked as INFO and more serious none-errors could be marked as WARNING.