XSB Src (SVN)-old

Took out spurious warning from predicate_property.

Test for incremental tabling problem that fixed in a prior commit, where callnode-> recomputable
was not properly resent on propagate_no_change.

Changes to fix a bug in tripwire version of maxans.

Added a new test for test...maxans.

Changes for
* table...maxan
* 'custom' option for tripwires
* Fix for coredump on undefined predicates involved in ?- queries in compiled files.

More for maxans + updated debugging messages for incremental tabling (commented out in tables.c)

Changes to

* Fix bug where callnode->recomputable was not reset to
COMPUTE_DEPENDENCIES_FIRST when no change was propagated.
* Added table as maxans
* Added tripwire option 'custom' rather than overloading 'suspend'

Documented table ... as ... maxans(N).

Change standard to restructure how open_url is done. Makes it
cleaner.
Also add functor/4 (functor(Term,Module,Functor,Arity) to make dealing
with terms in modules simpler.

Split out code to handle opening url streams. To allow import to do the
necessary dynamic loading, with need for explicit module modifiers.