[crossfire] MLab maps, again

[Andy Fuchs]

While looking at these maps I found Permanent (unique 1) chests and
similar containers at "/mlab/cdcbigstore2f", which I think should cost
a great deal more.  Also a few shops (bookshop, forgot other ones)
allow unpaid items to leave them.
Also a unique floored area exists that a key is required to enter. 
However this key is obtained with only a password in the basement of
the tavern.