No logic changes. The point of this commit is to make the next one, which will
change the way logging is controlled, easier to read.

(1) waf check -v no longer spams log messages to stdout (Gitlab issue #19).

(2) ntpdig now suppresses logging to stdout (long-time to-do from Hal Murray).

(3) The (not yet working) TESTFRAME modes wuill fully suppress logging.