XSB Src (SVN)-old

Added multifile fact for "refined" multifile name, inc filename, to allow
multifile check for undefinedness.

Check for multifile before throwing undefined error.

New tests for fixed sym_diff_db, and for all the new predicates for set
operations within a single DB (the so-called *_in_db predicates.)

in curl.P: added post_data/3, which includes response from the server.

Improved retractall_in_db. Made it more general and more efficient.

Added tests for retract_in_db, which has been made more general,
and more efficient.

New tests for the xxx_dbi() versions of the db operations
(i.e., those that work with interned trie database terms.)

Fixed bug in disjoint_db/2.
For each exporte xxx_db() predicate, added corresponding xxx_dbi() predicate
with same functionality, but takes intern_termhash codes for input trie
databases, and produces them for output databases. By using these, the
user can efficiently table these databases, no matter how large.

Added tests of new prolog_db set operations.

Added documentation of new prolog_db set operations.