New shell script Addmodule.sh makes it easier to add a new optional

module by editing Makefile and config.c in all the right places.
Used it to add most modules currently known.  Added markers to help
the script to Makefile and config.c.

Modules/config.c.in

@@ -220,6 +220,7 @@ extern void initcl();
 #ifdef USE_TIME
 extern void inittime();
 #endif
+/* -- ADDMODULE MARKER 1 -- */
 
 struct {
 	char *name;
@@ -350,5 +351,7 @@ struct {
 	{"time",	inittime},
 #endif
 
+/* -- ADDMODULE MARKER 2 -- */
+
 	{0,		0}		/* Sentinel */
 };