deprecate wxDC::SetClippingRegion(wxRegion) overload and replace it with SetDeviceCli...

deprecate wxDC::SetClippingRegion(wxRegion) overload and replace it with SetDeviceClippingRegion() to avoid confusion due to use of different kind of coordinates in this and other overloads of the same function; also rename wxDCImpl::DoSetClippingRegionAsRegion() to DoSetDeviceClippingRegion(); finally use bounding box of the region passed to wxDCClipper ctor to avoid interpreting coordinates differently for different ctors of the same class (see #8970)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@54024 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775