Scan command line for --threads/--nothreads

[mvidner]

Related to https://bugzilla.suse.com/show_bug.cgi?id=1139967 and its fix libyui/libyui-qt#110, "pollEventInternal/UI.PollInput would produce no events"

This is a way to enable yui threads in the examples. Which makes them fail with

...
<_M_> [qt-ui] YQUI.cc:105 YQUI(): This is libyui-qt 2.50.4
<ERR> [qt-ui] YQUI.cc:687 qMessageHandler(): <libqt-fatal> QWidget: Must construct a QApplication before a QWidget
Aborted (core dumped)

[coveralls]

Pull Request Test Coverage Report for Build 409

• 0 of 6 (0.0%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.002%) to 1.963%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/YUILoader.cc	0	6	0.0%

Totals
Change from base Build 407:	-0.002%
Covered Lines:	129
Relevant Lines:	6570

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💛 - Coveralls