Add a hidden option for skipping the introduction in reporting assistant

That introduction page is not really useful/needed for users and
developers who have used drkonqi for enough times.

No GUI change involved, so it is now a hidden option in drkonqirc:

    [ReportAssistant]
    SkipIntroduction=true

FEATURE: 313426
REVIEW: 108454

FIXED-IN: 4.11.0