tennames, numstr): Replace by static local variables in their only
user.
(relates): Move from global/misc.c to common/nat.c.
(att_mode): Move from global/misc.c to subs/attsub.c.
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.
EMPPATH() to use EMPDIR. This avoids triggering MSVC bugs, and drops
support for traditional, pre-ISO cpp. Closes#753935.
(gamedir, lostfil, playerbin, updatebin): Unused, remove.