XSB Src (SVN)-old

Changes to Makefule to generate predicate index. Also some
adjustments to documentation for new trie model.

One more example of incorrect release size, this time when expanding
the string hash table. Now for the cases I tested, all blocks are freed
with the same length that they were allocated. There is still some
discrepancy with the amount of table space claimed as allocated in statistics
and the amount of space obtained for table_space through mem_alloc (and
friends.) That remains to be accounted for.

Fixed a bug in accounting for mem_dealloc size in a particular case
of table processing. This makes the table space statistics (more) correct.

Fixed a memory leak in tabling: the bucket-array for hashing in tries
was not being released (unless it had been expanded.) There was a test
for larger size than initial, which I removed. I assume this was leak
was probably introduced when the initial bucket-array became independently
allocated (?). With this change, abolish_all_tables and abolosh_table_pred
give back all the memory in my tests.

Finished update of table abolish/gc routines by making gc mark
check delay list (didn't do this last night because I wanted to
be fresh). Also did some minor code refactoring and optimization
for these routines.

Minor updates for documentation of tries and table abolishes.

Extended (almost) all the marking routines for tabled predicates
so that subgoals in the heap delay list are checked. This rather
obscure bug caused a crash in a Flora program for defeasible
logic. I'll try to finish that part tomorrow.

The problem was that space was reclaimed for a table T that had a
delay element in the heap pointing to it. When the answer with
the delay element was added, the engine tried to adjust the
backpointers for T and crashed.

Also made some minor ajustments for efficency to some of the
marking functions. And I changed abolish_table_info to the
clearer abolish_all_tables.

ABOLISH_TABLE_INFO -> ABOLISH_ALL_TABLES

Took out explicit definitions of undefined.

Fixed dumb typo in switch to abolish tables transitively vs singly.