1. Add a substitution of the |SVN| string using subprocess;
2. Add the latest ArtProvider stuff (and replace `ArtID` and `ArtClient` parameter types with `string`).
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxPython/Phoenix/trunk@71149 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
