Add wxArtProvider using Tango icons.

The icons are embedded as PNG images directly in the source code to avoid the
need for installing them. This does make the library larger though so provide
a wxUSE_ARTPROVIDER_TANGO option to turn the new code and associated bloat off.
Also turn it off by default under wxGTK as the native art provider is used
there anyhow.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66505 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/chkconf.h

@@ -407,6 +407,14 @@
 #   endif
 #endif /* !defined(wxUSE_ANIMATIONCTRL) */
 
+#ifndef wxUSE_ARTPROVIDER_TANGO
+#   ifdef wxABORT_ON_CONFIG_ERROR
+#       error "wxUSE_ARTPROVIDER_TANGO must be defined, please read comment near the top of this file."
+#   else
+#       define wxUSE_ARTPROVIDER_TANGO 0
+#   endif
+#endif /* !defined(wxUSE_ARTPROVIDER_TANGO) */
+
 #ifndef wxUSE_AUTOID_MANAGEMENT
 #   ifdef wxABORT_ON_CONFIG_ERROR
 #       error "wxUSE_AUTOID_MANAGEMENT must be defined, please read comment near the top of this file."
@@ -1615,6 +1623,17 @@
 #endif /* wxUSE_FILEDLG */
 
 /* common dependencies */
+#if wxUSE_ARTPROVIDER_TANGO
+#   if !(wxUSE_STREAMS && wxUSE_IMAGE && wxUSE_LIBPNG)
+#       ifdef wxABORT_ON_CONFIG_ERROR
+#           error "Tango art provider requires wxImage with streams and PNG support"
+#       else
+#           undef wxUSE_ARTPROVIDER_TANGO
+#           define wxUSE_ARTPROVIDER_TANGO 0
+#       endif
+#   endif
+#endif /* wxUSE_ARTPROVIDER_TANGO */
+
 #if wxUSE_CALENDARCTRL
 #   if !(wxUSE_SPINBTN && wxUSE_COMBOBOX)
 #       ifdef wxABORT_ON_CONFIG_ERROR