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

include/wx/os2/setup0.h

@@ -912,11 +912,25 @@
 // wxAcceleratorTable/Entry classes and support for them in wxMenu(Bar)
 #define wxUSE_ACCEL 1
 
+// Use the standard art provider. The icons returned by this provider are
+// embedded into the library as XPMs so disabling it reduces the library size
+// somewhat but this should only be done if you use your own custom art
+// provider returning the icons or never use any icons not provided by the
+// native art provider (which might not be implemented at all for some
+// platforms) or by the Tango icons provider (if it's not itself disabled
+// below).
+//
+// Default is 1.
+//
+// Recommended setting: 1 unless you use your own custom art provider.
+#define wxUSE_ARTPROVIDER_STD 1
+
 // Use art provider providing Tango icons: this art provider has higher quality
 // icons than the default ones using smaller size XPM icons without
 // transparency but the embedded PNG icons add to the library size.
 //
-// Default is 1.
+// Default is 1 under non-GTK ports. Under wxGTK the native art provider using
+// the GTK+ stock icons replaces it so it is normally not necessary.
 //
 // Recommended setting: 1 but can be turned off to reduce the library size.
 #define wxUSE_ARTPROVIDER_TANGO 1