QToolTip - add static showText with time.

It is nice to be able to control how long time a tooltip is shown.
This is the first part of solving:

Task-number: QTBUG-1016

Change-Id: I8e313df8a2acdc5ccc91d9c8ce956c30c76daf4b
Reviewed-by: David Faure (KDE) <faure@kde.org>
Core: QDebug and comparison operator support metatypes.

This patch adds a way to enable operator<, operator== and operator<<
into QDebug for QVariants with custom types.

Change-Id: I3d12d891bd7252ad2b8f1de69bced354800a1f29
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>