wxHelpProvider::RemoveHelp, which is now called from ~wxWindowBase. Without cleaning up the hash tables, reused window addresses will cause the CS help to fail rather comically over time. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@15754 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775