Clean up some misplaced #includes.

Random .h files have no business including postgres-fe.h (or postgres.h).
If that wasn't the first #include done by the calling .c file, it's the
.c file that's broken.  Noted while prepping Kyotaro Horiguchi's psql
lexer refactoring patch.

src/bin/psql/common.h

@@ -8,10 +8,9 @@
 #ifndef COMMON_H
 #define COMMON_H
 
-#include "postgres_fe.h"
 #include <setjmp.h>
-#include "libpq-fe.h"
 
+#include "libpq-fe.h"
 #include "print.h"
 
 #define atooid(x)  ((Oid) strtoul((x), NULL, 10))

src/bin/psql/create_help.pl

@@ -59,7 +59,6 @@ print HFILE "/*
 #ifndef $define
 #define $define
 
-#include \"postgres_fe.h\"
 #include \"pqexpbuffer.h\"
 
 struct _helpStruct
@@ -84,6 +83,7 @@ print CFILE "/*
 
 #define N_(x) (x)				/* gettext noop */
 
+#include \"postgres_fe.h\"
 #include \"$hfile\"
 
 ";

src/bin/psql/mainloop.h

@@ -8,8 +8,6 @@
 #ifndef MAINLOOP_H
 #define MAINLOOP_H
 
-#include "postgres_fe.h"
-
-int			MainLoop(FILE *source);
+extern int	MainLoop(FILE *source);
 
 #endif   /* MAINLOOP_H */