This patch changes the Event drawing so it can display tooltips. It is now
the responsibility of the item to show / hide a tooltip.
A bit of code-refactoring got on here too because I was using only
QGraphicsItem calls and I wanted to use a hover in / hover out event
to show / hide the tooltip.
Signed-off-by: Tomaz Canabrava <tcanabrava@kde.org>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>