Move AppName to lib-utility...

... It makes more sense there, at an even lower level than lib-files.  Avoid
type wxString.

libraries/lib-utility/ModuleConstants.cpp

@@ -0,0 +1,21 @@
+/**********************************************************************
+
+  Audacity: A Digital Audio Editor
+
+  ModuleConstants.cpp
+
+  Paul Licameli
+
+**********************************************************************/
+
+#include "ModuleConstants.h"
+
+// We want Audacity with a capital 'A'
+// DA: App name
+const std::wstring AppName =
+#ifndef EXPERIMENTAL_DA
+   L"Audacity"
+#else
+   L"DarkAudacity"
+#endif
+;