remove (hilarious) defaults for various constants getpath.c needs

Modules/getpath.c

@@ -101,25 +101,8 @@
 #endif
 
 
-#ifndef VERSION
-#define VERSION "2.1"
-#endif
-
-#ifndef VPATH
-#define VPATH "."
-#endif
-
-#ifndef PREFIX
-#  define PREFIX "/usr/local"
-#endif
-
-#ifndef EXEC_PREFIX
-#define EXEC_PREFIX PREFIX
-#endif
-
-#ifndef PYTHONPATH
-#define PYTHONPATH PREFIX "/lib/python" VERSION ":" \
-              EXEC_PREFIX "/lib/python" VERSION "/lib-dynload"
+#if !defined(PREFIX) || !defined(EXEC_PREFIX) || !defined(VERSION) || !defined(VPATH)
+#error "PREFIX, EXEC_PREFIX, VERSION, and VPATH must be constant defined"
 #endif
 
 #ifndef LANDMARK