not just the given one
2. added wxRegionIterator copy ctor and assignment operator
3. fixed wxRegionIterator::operators++() to do what they say
4. generic code cleanup
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@17310 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775