Major changes in this version:

1) Specification of data models has been separated from specification
   of networks, in order to facilitate the eventual use of these same
   models with functions defined in other ways than by networks.  The
   model specification arguments of net-spec have disappeared; they
   are instead given to the new model-spec program.

2) Models for survival data have been added.  They should be regarded
   as experimental, however.

3) Documentatation on data models has been expanded and moved out of 
   net-spec.doc, to the new model-spec.doc (in util).  Documentation
   on prior specifications has been moved from net-prior.doc to
   prior.doc.  Many revisions have been made to other documentation

4) A number of new Markov chain Monte Carlo methods have been added.
   These may or may not be of any use for neural network models.

5) The method for sampling top-level hyperparameters has been changed
   from the rejection method described in section A.2.2 of the thesis
   to the adaptive rejection sampling method due to Gilks and Wild.
   The message, "WARNING: Over 10000 tries in one call of cond_sigma"
   will now never appear.

6) The 'rand' module is now automatically told to find its file of
   natural random numbers ('randfile') in the 'util' directory where
   it is located.  This is done in 'util.make', which should be 
   changed if some other behaviour is desired.

Note that modification (1) above is not upwardly compatible, though it
should be very easy to modify command files to use the new scheme.
Also, log files created with the previous version cannot be read with
this version.

SPECIAL NOTE:  This is the version of the software that Carl Rasmussen
used for the tests reported in his thesis.

Known bugs.

1) The facility for plotting quantities using "plot" operations in xxx-mc
   doesn't always work for the first run of xxx-mc (before any
   iterations exist in the log file).  A work-around is to do a run of
   xxx-mc to produce just one iteration before attempting a run of
   xxx-mc that does any "plot" operations.