Applied patch [ 648042 ] Erase background error

Applied patch [ 648042 ] Erase background error

When erasing the background with a transparent
background the logical origin of the provided DC is (re)
set, but not restored to the old value. Restoring the old
value is needed because the DC is/can be shared with
the real draw code...

This patch solves problems like mentioned in bug report
#635217 and problems like controls (like radio controls
etc) that disappear when moving the mouse over them or
clicking on them...

Hans Van Leemputten

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@18141 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775