Add wxUSE_MARKUP and wrap SetLabelMarkup() in it.

Make it possible to disable all the new markup-related code by setting
wxUSE_MARKUP to 0 in setup.h or using configure --disable-markup option.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@67062 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/markupparser.cpp

@@ -23,8 +23,7 @@
     #pragma hdrstop
 #endif
 
-#ifndef WX_PRECOMP
-#endif // WX_PRECOMP
+#if wxUSE_MARKUP
 
 #include "wx/private/markupparser.h"
 
@@ -473,3 +472,5 @@ wxString wxMarkupParser::Strip(const wxString& text)
 
     return output.GetText();
 }
+
+#endif // wxUSE_MARKUP