Application's QEvent::Tooltip show timeout should be customizable

Right now the core tooltips initialization for the whole program is hardcoded (literally) within QApplication::notify().
(700ms for initial show, 20 for reshow.)

This is unfortunate. These should be properties much like drag dist.

Also, if one wants diff intervals (for the whole app), he will have to define new QEvent::Type,
because its impossible to even stop sending these default tooltip events! (Without eating all timer events, which is certainly not a good idea)