Applied patch [ 590247 ] Fix bad calculation of listctrl update.

Applied patch [ 590247 ] Fix bad calculation of listctrl update.

In wxGenericListCtrl when removing single items a call to
RefreshAfter would cause bad things to happen in GTK/X11.
It would under certain circumstances put Xlib into an
exponential memory and cpu usage mode. Causing
eventual core dump but not before using all memory and
swap.

The problem is that RefreshAfter is passing a negative
height rectangle refresh to GTK/X11. This stems from a mixture
of using scrolled and unscrolled values to calculate the
update region.

This patch fixes the problem... by transforming to scrolled
values earlier. And also adds one optimization to not
update when the item is below the visible area.

Tested on GTK.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@16402 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775