[IMPR] Show global options with pwb.py
[IMPR] Show global options with pwb.py

Enable global options handling even if no filename is given for
pwb.py. This makes it possible that pwb.py -help prints global
options which are handled py pwb.py wrapper script and provides
global options even if a script does not call
pywikibot.handle_args()

Change-Id: I9524c1f1a95a0db21e94a5875831ef4f4f039b3d

wikimedia/pywikibot-core,wikimedia/pywikibot-core