cfgtool: add external VST functions used by libardour

cfgtool/cfgtool.cc

@@ -45,3 +45,9 @@ int main (int argc, char **argv) {
 
 	return 0;
 }
+
+
+#include "ardour/vst_types.h"
+int vstfx_init (void*) { return 0; }
+void vstfx_exit () {}
+void vstfx_destroy_editor (VSTState*) {}

cfgtool/wscript

@@ -13,6 +13,9 @@ def configure(conf):
     autowaf.configure(conf)
 
 def build(bld):
+    if bld.is_defined('WINDOWS_VST_SUPPORT') and bld.env['build_target'] != 'mingw':
+	    return;
+
     obj = bld (features = 'cxx c cxxprogram')
     obj.source       = 'cfgtool.cc'
     obj.target       = 'cfgtool'