Add wxUSE_ARTPROVIDER_STD build option.

Make it possible to exclude wxDefaultArtProvider from build. Now that a
Tango-based provider exists, it may make sense to disable the standard bitmaps
if the program doesn't need the few of them not provided by Tango anyhow.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66506 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/artstd.cpp

@@ -20,6 +20,8 @@
     #pragma hdrstop
 #endif
 
+#if wxUSE_ARTPROVIDER_STD
+
 #ifndef WX_PRECOMP
     #include "wx/image.h"
 #endif
@@ -246,3 +248,5 @@ wxBitmap wxDefaultArtProvider::CreateBitmap(const wxArtID& id,
 
     return bmp;
 }
+
+#endif // wxUSE_ARTPROVIDER_STD