1. Don't destroy the control in wxToolBar::RemoveTool() as this prevents
it from being added back with is the purpose of using RemoveTool() rather
than DeleteTool().
2. Call wxToolBarTool::Attach/Detach() from the base code, not just from wxMSW
and wxMac (wasn't called by wxGTK at all).
3. Allow adding back the removed control tool in wxGTK.
4. Add test for removing/adding back a control tool to the sample.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52840 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
