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/common/file.c

@@ -424,8 +424,6 @@ ef_flags(int type)
 time_t
 ef_mtime(int type)
 {
-    extern time_t fdate(int fd);
-
     if (empfile[type].fd <= 0)
 	return 0;
     return fdate(empfile[type].fd);

src/lib/common/keyword.c

@@ -110,8 +110,6 @@ kw_find(s_char *name)
 s_char *
 kw_parse(int type, s_char *text, int *data)
 {
-    s_char *get_time(s_char *ptr, int *data);
-    s_char *weekday(s_char *ptr, int *data);
     s_char *next;
 
     while (isspace(*text))

src/lib/common/log.c

@@ -51,7 +51,7 @@
 static s_char *logfile = 0;
 
 s_char *
-getlogfile()
+getlogfile(void)
 {
     return (s_char *)logfile;
 }

src/lib/common/path.c

@@ -441,19 +441,19 @@ bp_coord_hash(struct as_coord c)
 }
 
 void
-bp_enable_cachepath()
+bp_enable_cachepath(void)
 {
     as_enable_cachepath();
 }
 
 void
-bp_disable_cachepath()
+bp_disable_cachepath(void)
 {
     as_disable_cachepath();
 }
 
 void
-bp_clear_cachepath()
+bp_clear_cachepath(void)
 {
     as_clear_cachepath();
 }

src/lib/common/sectdamage.c

@@ -49,6 +49,7 @@
 #include "gen.h"
 #include "subs.h"
 #include "lost.h"
+#include "combat.h"
 
 int
 sect_damage(struct sctstr *sp, int dam, struct emp_qelem *list)
@@ -93,7 +94,6 @@ sectdamage(struct sctstr *sp, int dam, struct emp_qelem *list)
     struct plnstr plane;
     double real_dam;
     int eff;
-    double sector_strength();
 
     /* Some sectors are harder/easier to kill..   */
     /* Average sector has a dstr of 1, so adjust  */