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/server/idle.c

@@ -37,12 +37,12 @@
 #include "empthread.h"
 #include "proto.h"
 #include "prototypes.h"
+#include "optlist.h"
 
 /*ARGSUSED*/
 void
 player_kill_idle(void *argv)
 {
-    extern int max_idle;
     struct player *p;
     time_t now;