Rewrite commit 1bc0f0f without further changes to lib-src...

... Reuse the external function registration added earlier in 2.3.0
development, for support of internationalization in Nyquist.

This way, we avoid making cyclic static linkage dependencies between the
library and the application.

src/commands/ScriptCommandRelay.cpp

@@ -138,15 +138,9 @@ int ExecCommand2(wxString *pIn, wxString *pOut)
 
 
 
-#ifdef __cplusplus
-extern "C" {
 // The void * return is actually a Lisp LVAL and will be cast to such as needed.
 extern void * ExecForLisp( char * pIn );
 extern void * nyq_make_opaque_string( int size, unsigned char *src );
-};
-
-
-#endif
 
 void * ExecForLisp( char * pIn ){
    wxString Str1( pIn );