I_BAR, I_FOOD, I_OIL, I_LCM, I_HCM, I_UW, I_RAD, I_MAX): Turn macros
into enumeration constants.
(i_type): New. Use where appropriate. No functional changes, except
that I_NONE is now catched properly in a few places.
freshly extended trade file makes sense. When set() removes a lot,
simply zero the slot.
(set): Initialize trd_uid.
(trade_check_ok): Use check_land_ok() & friends instead of doing it by
hand, but wrong. This fixes bying planes and land units loaded on
ships that moved after loading.
(check_trade_ok): New.
(trade_check_ok): Use it. Remove unused argument lot. Callers
changed.
member com_type from mnemo character to item type.
(whichitem): Unused, remove.
(check_market): Use full item name instead of mnemo in telegrams.
(display_mark): Separate arguments for item type and cheapest only.
Cheapest only of specific item type is not implemented.
(rese): Guard against bad com_type. Delete some code that had no
effect.
To save space, the ancients invented `variables': a collection of
key-value pairs, missing means zero value, space for `enough' keys.
This complicates the code, as assigning to a `variable' can fail for
lack of space. Over time, `enough' increased, and for quite some time
now `variables' have been *wasting* space. This changeset replaces
them, except in struct mchrstr, struct lchrstr and struct pchrstr,
where they are read-only, and will be replaced later. It is only a
first step; further cleanup is required. To simplify and minimize
this necessarily huge changeset, the new item[] arrays have an unused
slot 0, and the old variable types V_CIVIL, ... are still defined, but
must have the same values as the item types I_CIVIL, ...
its code is obviously not in working order. Remove.
(minmult, maxmult, configkeys): Unused configuration parameters,
remove.
(tradedesc): Remove code related to mult that had no effect.
(multread, commread, commwrite, commamt, commset, multset, commprice):
Dangerous, because code bypasses ef_read() & friends, remove.
(diss): Commodity cleanup uses the above, remove. Command is disabled
and unlikely to work anyway.
