[developers] updates in the LOGON tree

[Stephan Oepen]

colleagues,

i finally migrated the LOGON tree to using Allegro CL 10.0 (from 8.2,
for the past many years).  in principle, there should be no visible
changes to users of the run-time images.

but it appears the new compiler (using the LOGON compiler setting)
generates faster and less robust code: i have already analyzed one
previously unnoticed bug, where calling subseq() with a negative start
index apparently used to quietly return an empty sequence but now
(correctly) raises an exception.

in other words, there may after all be unexpected behavior, most
likely from exposing ‘sleeper’ bugs.  hence, please ‘make update’ your
LOGON tree (or just get a fresh installation), watch out for suprising
behavor, and let me (and the LOGON list) know your findings!

except for dan, i am not aware of LOGON users running from sources
nowadays.  if you do, once you ‘svn up’ below the optional add-on
‘franz/linux.x86.64/’ you will need a fresh ‘devel.lic’ license file
for Allegro CL version 10.0.

—part of my motivation for taking this move have been recurrent fatal
errors (SEGV) over the past several months in the ERG on-line
demonstrator, which have put a few dents in our previously stellar
uptime record.  i optimistically hope that these errors will be gone
now!  come to think of it, they might actually be related to the
subseq() bug mentioned above ...

best wishes, oe