XSB Src (SVN)-old

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.

Added sentence in compare about two terms not being equal if their
main functor symbols are in different modules.