Supply prototypes where possible. This uncovered type errors with

thread entrypoints:
(lwpSelect, shutdown_sequence): Parameters didn't match thread entry
point prototype.
(lwpEntryPoint): Arguments didn't match thread entry point prototype.

Change linkage of functions without prototype declaration to static
where possible.

Remove some superflous declarations, replace others by suitable
includes.

src/lib/update/distribute.c

@@ -45,14 +45,13 @@
 #include "update.h"
 #include "subs.h"
 #include "common.h"
+#include "prototypes.h"
 
 int
 dodistribute(struct sctstr *sp, int imex, s_char *path, double dist_i_cost,
 	     double dist_e_cost)
 	  /* import or export? */
 {
-    struct sctstr *getdistsp();
-    float distpathcost();
     struct ichrstr *ip;
     struct sctstr *dist;
     int amt;

src/lib/update/finish.c

@@ -72,9 +72,9 @@ static s_char *finish_path = "h";	/* Placeholder indicating path exists */
 #endif /* SAVE_FINISH_PATHS */
 
 static void assemble_dist_paths(struct distinfo *distptrs);
-s_char *BestDistPath();
+s_char *BestDistPath(s_char *, struct sctstr *, struct sctstr *, double *, int);
 s_char *ReversePath(s_char *path);
-double pathcost();
+double pathcost(struct sctstr *, s_char *, int);
 
 void
 finish_sects(int etu)
@@ -240,8 +240,7 @@ assemble_dist_paths(struct distinfo *distptrs)
     }
 }
 
-s_char
-*
+s_char *
 ReversePath(s_char *path)
 {
     s_char *patharray = "aucdefjhigklmyopqrstbvwxnz";

src/lib/update/land.c

@@ -121,7 +121,6 @@ upd_land(register struct lndstr *lp, int landno, register int etus,
     int vec[I_MAX + 1];
     int cvec[I_MAX + 1];
     int n;
-    double techfact(int, double);
     int min = morale_base - (int)np->nat_level[NAT_HLEV];
     int mult;
     extern double money_land;
@@ -245,7 +244,6 @@ static int
 landrepair(register struct lndstr *land, int *vec, struct natstr *np,
 	   int *bp, int etus)
 {
-    extern int mil_dbl_pay;
     extern int land_grow_scale;
     register int delta;
     struct sctstr *sp;

src/lib/update/mobility.c

@@ -56,7 +56,7 @@ static void do_mob_plane(register struct plnstr *, register int);
 static void do_mob_sect(register struct sctstr *sp, register int etus);
 static void do_mob_ship(register struct shpstr *, register int);
 
-int
+static int
 increase_mob(time_t * counter, float mult)
 {
     time_t secs;

src/lib/update/nav_ship.c

@@ -241,7 +241,6 @@ nav_loadship(register struct shpstr *sp, natid cnum)
 int
 nav_ship(register struct shpstr *sp)
 {
-    extern double techfact(int, double);
     struct sctstr *sectp;
     s_char *cp, item;
     int stopping;

src/lib/update/nav_util.c

@@ -59,8 +59,6 @@
 int
 check_nav(struct sctstr *sect)
 {
-    extern struct dchrstr dchr[];
-
     switch (dchr[sect->sct_type].d_flg & 03) {
     case NAVOK:
 	break;

src/lib/update/revolt.c

@@ -144,7 +144,6 @@ revolt(struct sctstr *sp)
 void
 guerrilla(struct sctstr *sp)
 {
-    extern s_char *effadv();
     struct sctstr *nsp;
     int recruit;
     int move;
@@ -168,9 +167,7 @@ guerrilla(struct sctstr *sp)
     int val;
     int oldmob;
     struct lndstr *lp;
-    s_char *nxtitemp(struct nstr_item *np, int owner);
     struct nstr_item ni;
-    extern double hap_fact();
 
     mc = cc = 0;
     recruit = 0;
@@ -463,7 +460,6 @@ take_casualties(struct sctstr *sp, int mc)
     int cantake;
     int nunits = 0, each, deq;
     struct lndstr *lp;
-    s_char *nxtitemp(struct nstr_item *np, int owner);
     struct nstr_item ni;
 
     /* casualties come out of mil first */

src/lib/update/ship.c

@@ -445,7 +445,6 @@ feed_ship(struct shpstr *sp, register int *vec, int etus, int *needed,
     int starved, lvec[I_MAX + 1];
     struct nstr_item ni;
     struct lndstr *lp;
-    s_char *nxtitemp(struct nstr_item *np, int owner);
 
     if (opt_NOFOOD)
 	return 0;		/* no food no work to do */