Trader items are now inside tables, and thus not in the block
item lists. Thus it is necessary to scan the global item vector
and look up blocks by coords.
Based on dfusion code, with lots of safety checks added. Supports two
swap modes: transient and permanent; the former does a minimal change
and is intended for managing companion inventory. The permanent one
performs all known actions necessary to turn it into the real adventurer.
Note: the transient mode is a hack and may cause the game to crash
if not reverted while within range of the real adventurer unit.
Alexander Gavrilov
Quietust
Petr Mrázek