Some changes to how log files are handled; this too way too long to

do!

The original operation was to save up every log file forever in the
work directory, and copy that out to both the user directory and the
info directory (long term archive). When I cleaned /proj on ops
yesterday of all this old cruft, I recoved 17GB of disk space. Yow!

So, the new operation is:

* Only files that end in .log are copied to the user directory. No
  longer copying out .top, .ptop, and a couple of other logs; 99% of
  users never look at these things. We still have them available to us
  though, on boss.

* At the beginning of each swap operation, clean out the work
  directory of all the old log files. These are named a variety of
  ways, so I use some pattern patches to do this.

* Jigger the names a little so that we do not name things in the form
  "$$.log", to avoid copying out different named files to the user
  directory each time; instead link the .log file to the real output
  file so that it gets overwritten each time, while still getting the
  per-swap files for long term storage.