Declare all configuration variables in optlist.h. Include that

instead of declaring them all over the place.  This uncovered type
errors:
(s_p_etu, adj_update): Defined long, sometimes declared int.  Kills
big endian machines where sizeof(long) != sizeof(int).  Change to
int.

(set_option, delete_option, optstrset, intset, floatset, doubleset,
longset, optionset, optiondel, worldxset): Change linkage to static.

src/lib/player/accept.c

@@ -193,7 +193,6 @@ player_wakeup(struct player *pl)
 void
 player_accept(void *argv)
 {
-    extern s_char *loginport;
     struct sockaddr_in sin;
     struct servent *sp;
     int s;

src/lib/player/dispatch.c

@@ -51,7 +51,6 @@ dispatch(s_char *buf, s_char *redir)
 {
     extern struct cmndstr player_coms[];
     extern int update_pending;
-    extern int max_btus;
     struct natstr *np;
     struct cmndstr *command;
     int cmd;

src/lib/player/init_nats.c

@@ -74,9 +74,6 @@ init_nats(void)
 static int
 nat_cap(int btu)
 {
-    extern int s_p_etu;
-    extern int max_btus;
-    extern float btu_build_rate;
     struct sctstr sect;
     struct natstr *np;
     double d;