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/common/log.c

@@ -47,6 +47,7 @@
 #include "deity.h"
 #include "player.h"
 #include "common.h"
+#include "optlist.h"
 
 static s_char *logfile = 0;
 
@@ -63,7 +64,6 @@ void
 loginit(void)
 {
     extern s_char program[];
-    extern s_char *datadir;
     s_char buf[1024];
 
 #if !defined(_WIN32)