SetPulseRate() even if it is 0. BView::_Attach() and BView::SetFlags() now
just set the previous pulse rate again (which will start pulsing in case
there is no fPulseRunner yet).
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19850 a95241bf-73f2-0310-859d-f6bbb57e9c96