XSB Src (SVN)-old

Fixed fat-fingered typo...

Fixed bug in builtin file_set_character_set.

Add predicate: file_set_character_set/2 to take a stream indicator and a
character set identifier and set the charset for that stream as indicated.

Added option to file_function to set charset of open file (intended for
use with userout or userin).

Changed (partially) calls to stat to be calls to __stat64 on windows64
(with corresponding change to stat buffer) since stat seems to have
recently changed to fail on files with sizes > 2^31-1. Changed call
at open, where it bit us, but didn't change all stat calls. Got too
tricky, so can change those as we discover problems...

Several refinements.

Manual: fixed incorrect reference to Character Sets.
Windows: fixed xsb_configuration, which was missing build_date.

ignored *_new files (on git)
updated banners

Yet another bug in traverse_variant_answer_trie - those pesky hash
tables again. In this case the traversal was not properly pushing
information pertaining to hash tables onto the stack when the
traversal occurred via encountering a hash node during traversal
of the unseen nodes of the trie. Another case, where information was
pushed onto the stack when initialziing information from a segment of
choice points was in fact working properly (a prior bug).

This fix solves a CMU-SEI problem, but I need to look at it with fresh
eyes to see if its general or not.

Adding tests from CMU SEI, mostly to do with the view consistency portion of incremental tabling.

Fix for a bug in the view consistency portion of incremental tabling.
The problem was in ensuring that the list collected onto the heap was
properly preserved. The problem is that you need to create the list
on the heap, but you're doing it via a meta-operation on a choice
point that isn't at the top of the choice point stack. Originally, I
thought that setting hfreg worked for this, but a prior test broke it
during GC. (I didn't look into why.) My prior fix was simply to
comment out the line of code, as I had forgotten exactly why I'd set
hreg to hfreg. This fixed the immediate bug, but wasn't entirely
correct as its possible that if the CP changed had other choice points
on top of it, the hreg would be improperly set when those other choice
points were backtracked into. This problem could have manifested
itself in a number of ways, but heap gc caught it this time, as the
offset of the hreg for the view conssitency choice point lay outside
the heap array used when GC marks from the CP stack.

So, my fix was to run from breg to the coalesced choicepoint, setting
all of the cp_hregs to the new hreg. This is ok, as we know that the
new hreg is larger than the previous, since we just put stuff onto the
heap.