behave as reasonably expected and as described in the manual.
Previously a missing (null) value was always accepted if the ifsspec.ifs
file contained a default value, and several of the the included
code models worked that way. Where there was a useful default,
"no" has channged to "yes". Some models with a look-up table defined
by two parameters had such defaults that did nothing useful. Thay have
been given useful vector defaults. These changes should not affect
previously-working netlists.
Giles Atkinson
27eda59034