animated scroll until the rect becomes visible
it should not collide with kinetic scroll since the anim is stopped as
soon as amouse or wheel event is triggered
CCMAIL:plasma-devel@kde.org
svn path=/trunk/KDE/kdelibs/; revision=1027814
ATM, it uses timers to do the animation, the idea is to use factory pattern
and implement the animation with QProperyAnimation too (using Qt 4.6).
svn path=/trunk/KDE/kdelibs/; revision=1024929
