Cosmetic improvements/code cleanup:

- replace some function signatures of the form "some_type foo()" with
"some_type foo(void)"
- replace a few instances of a literal 0 being used as a NULL pointer;
there are more instances of this in the code, but I just fixed a few
- in src/backend/utils/mb/wstrncmp.c, replace K&R style function
declarations with ANSI style, remove use of 'register' keyword
- remove an "extern" modifier that was applied to a function definition
(rather than a declaration)

src/bin/psql/common.c

@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2004, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.91 2004/09/20 18:51:19 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/common.c,v 1.92 2004/10/10 23:37:40 neilc Exp $
  */
 #include "postgres_fe.h"
 #include "common.h"
@@ -268,7 +268,7 @@ handle_sigint(SIGNAL_ARGS)
  * Returns whether our backend connection is still there.
  */
 static bool
-ConnectionUp()
+ConnectionUp(void)
 {
 	return PQstatus(pset.db) != CONNECTION_BAD;
 }