Remove extra printouts.
Add "debug" FLAVOR, leaving debugging symbols out of "release" (normal)
builds. While this somewhats violates OpenBSD policy for shared libraries,
it shrinks Qt5 to more acceptable size numbers. And we do it this way
for Qt4 and KDE4 already, anyway.

Also, simple DEBUG/CFLAGS hack doesn't work for all Qt modules anyway.
OpenBSD-specific qmake options tweaks, mostly shrinking conf file.