XSB Src (SVN)-old

documented table_ops key for statistics.

Changes to add table_ops key to statistics/2.

Added table_ops key for statistics/2 and along the way did some
refactoring and rationalization of the routines that support
statistics, many of which went back to the PSB days.

Restructured a couple of fields (call to the subgoal and answers for a
subgoal) in VariantSF to save a little space under 64 bits. Also,
cleaned up some format specifiers for 64 bits in debug_xsb.c

Defined STaCK_USER_MEMORY_LIMIT

Defined GL_SPACE

Fixed some undefined references that popped up when moving library.tex from Vol 2 to Vol 1.

Made both glstack_realloc and tcpstack_realloc handle user-set limits,
and to back off by halves if the requested increment is not needed or
not permitted. (This was done only for glstack_realloc and the
system_limit.

While I was at it, I cleaned up some code, particularly in the calls
to glstack_realloc.

Update for error message and maintaining max_memory in Kbytes now, rather than bytes.

Updated test to account for changed text in a memory error.