+ fixed off-by-one which turned out to cause large memory overwrites
+ this is an old one, very hard to catch: 1) FreeBSD system, 2) a lot
  of clients (preferably 10K+), 3) exiting/reading from/writing to
  128+ clients at a time, 4) ircd version where the bug shows up clearly
  (on 7.3 WHOWASHASH gets corrupted, and somewhat later we have a core:
  whowas_add_history -> dlinkDelete)
        
This applies to ALL versions of hybrid since 7.0, but is known to 
disclose most noticeably under 7.3