NUK_BLD_WORK): New, to encapsulate the formula in one place.
(SCT_MINEFF): New. Use it instead of literal 20.
(buil): Use CANT_HAPPEN() for internal error.
(build_ship, build_land, build_bridge, build_nuke, build_plane,
build_tower): Simplify avail calculation.
(lupgr, supgr, pupgr): Charge 15% of total build avail instead of an
undocumented amount computed from build lcm and hcm.
(build_ship, build_land, build_bridge, build_nuke, build_plane,
build_tower, lupgr, supgr, pupgr): Fix reporting of required avail
when there's not enough. Closes#942823.
(lupgr, supgr, pupgr): Code printed cost rounded down, but required
and charged unrounded cost. Confusing. Round cost down, like the
build command. Closes#942811.
(UPGR_COST, UPGR_EFF, lupgr, supgr, pupgr): New UPGR_COST, UPGR_COST replace
literal values.
(show_bridge, show_tower): Don't claim bridge building requires
`workers' (whatever that is), since it doesn't.
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.
effect. Replace calls by struct assignment where possible. Replace
clear buffer, copy string to buffer by strncpy(). Use assignment to
clear when that's clearer. Replace overlapping copy through bounce
buffer by memmove(). Replace rest by standard memset() and memcpy().
Also use sizeof() instead of literal array sizes for robustness, and
instead of symbolic array sizes for clarity.
