Change in GNU Prolog version 1.0.0:

* official first release (Fri Apr 16)
* rewrite DCG in C (unification optimized, avoid ill-balanced conjunctions)
* fix bug

Change in GNU Prolog version 0.9.0:

* Calypso becomes GNU Prolog
* in-place installation facility
* fix compiler bug
* rewrite sorts built-in predicates and add in-place sorts predicates
* rewrite DCG translation
* rewrite all solutions built-in predicates

Change in Calypso version 1.0-beta7:

* use autoconf
* fix known bugs
* add :- built_in/0-1 and :- built_in_fd/0-1 directives
* complete C foreign interface

