Excise DL_EXPORT/DL_IMPORT from Modules/*. Required adding a prototype

for Py_Main().

Thanks to Kalle Svensson and Skip Montanaro for the patches.

Modules/signalmodule.c

@@ -469,7 +469,7 @@ SIGINT, SIGTERM, etc. -- signal numbers\n\
 A signal handler function is called with two arguments:\n\
 the first is the signal number, the second is the interrupted stack frame.");
 
-DL_EXPORT(void)
+PyMODINIT_FUNC
 initsignal(void)
 {
 	PyObject *m, *d, *x;