XSB Src (SVN)-old

Forgot to commit this earlier.

No longer setting hfreg = hreg at the end of find_the_visitors.

Recommitting, just to be sure.

Forgot to commit this with last release.

Fixed mpa_to_skel to generate psc record for 0-ary predicates in usermod
(as already done in other modules.)

fixed the configuration for mysql and odbc drivers in dbddrivers package.
fixed a crash in mysql driver when the db doesn't exist
recompiled the dlls of various packages (for w64)

Changed declaration of undefined to make it opaque and also used undefined().

Mostly added catch over calls ti _$main to reset current-directory
in case of an abort (or any throw) during its execution.
Also fixed minor (but annoying) bug in loader error message in which sometimes
said a predicate was in usermod when it wasn't.

Changed /dll to uppercase since a VS Express version needs it uppercase
(and mine is fine with it either way...)

Fixed problem in re-initializing answer counter. I had made a change last August to reinitizlize the answer
counter when performing incremental re-computation, but I put it into the wrong place, so that the counter was being
reinitialized at every call, not just at incremental recomputation. Easy to fix once I tracked down the problem.