[crossfire] Items that evolve all the time

[Mark Wedel]

  The complication is that if the map resets, there is no easy measure to know 
how long the objects in question have not been accessed.

  For maps swapped out and swapped back in, I agree that is a much easier 
problem, as you can easily know how long the map has been swapped.

  But for maps that reset, this is more a problem, because neither the overlay 
map nor the unique item maps contain any map header.  Thus, there is no 
convenient way right now to store when the map was saved out, and thus know how 
long the map has been swapped out.