(svn r3275) -Fix: [OSX] removed libpng support and error dialogs from jaguar crosscompiles to fix crash

unix.c

@@ -434,7 +434,7 @@ void ShowInfo(const char *str)
 
 void ShowOSErrorBox(const char *buf)
 {
-#if defined(__APPLE__)
+#if defined(__APPLE__) && !defined(JAGUAR_CROSSCOMPILE)
 	// this creates an NSAlertPanel with the contents of 'buf'
 	// this is the native and nicest way to do this on OSX
 	ShowMacDialog( buf, "See readme for more info\nMost likely you are missing files from the original TTD", "Quit" );