other. Ensure headers in include/ can be included in any order
(except for econfig-spec.h, which is special). New header types.h to
help avoid inclusion cycles. Sort include directives. Remove some
superflous includes.
(ef_elt_byname): New.
(nstr_match_val): Use it to generalize to arbitrary table with
uniquely named elements. Use ca_type to find table, remove parameter
type. Callers changed.
(nstr_mkselval): Adapt sanity check accordingly.
(NSC_TYPEID): No longer needed, remove, users changed to use
appropriate integer type instead. This fixes signedness of sector
selectors des and newdes.
(meta_type): Remove entry for NSC_TYPEID.
(nstr_coerce_val): Can't detect typeid - integer mismatch anymore.
Was nice to have; perhaps revive it later.
(meta_type): Add its entry.
(setnum, nstr_promote, nstr_exec_val): Deal with it. nstr_exec_val()
implements opt_HIDDEN by mapping unknown values to -1.
(natstr, nat_ca): Use it for member nat_relate. This also halves its
size. Fixes very minor leak: before, player could see relations to
all countries, regardless of contact.
(nation_relations): Add entry for -1.
