XSB Src (SVN)-old

Changes to fix problems with expanding VarEnumerator array, the array
that handles variable aliasing when tabling terms. When expanding
this array, we had been doing a realloc. However, expansion may occur
midway through copying a term into a table. If this happens there is
the possibility that the part of the term that is not yet copied could
point into the *old* VarEnumerator array. If this happens with a
realloc, we get a dangling pointer, which was the cause of a core dump
on some flora programs.

My fix was 1) to replace the realloc with a malloc and 2) to grow the
array more aggressively, by powers of 2. This leads to a small memory
leak in certain cases, but the leak is bounded by the current size of
the VarEnumerator array, and so will be insignificant.

Expandable depth stack working for MT engine.

Expandable depth stack for bounded rationality

Fixed bug I introduced when changing types for Integer.
Now throws intended error message.

Minor changes in translating DL rules.

Minor indexing change

A few accumulated minor changes.

Support renaming of rid's to crid's (and vice versa)

Fixed bug when hash computation overflows int. Happened when increasing
depth of star index lookahead.

Make print_pterm tail-recursive, so fewer C runstack overflows.
(Counts number of close-parens to print on exit, so can be tail-recursive.)