jwutils.log.set_flags() and .set_level() is not set until after all
commands are loaded. This can make debugging complicated. OTOH,
command-line parsing is also not done until all commands are loaded,
because they define the command line options. This commit adds some
poor man's command line parsing for fetching --log-level and
--log-flags only, and applying them before the commands are all
loaded.
Signed-off-by: Jan Lindemann <jan@janware.com>