XSB Src (SVN)-old

Added more builtins to be compiled to the builtin instruction.
Updated variable processing to better process non-first but not last
occurrences of variables.
Added processing of more builtin instruction forms, and released registers
when allowed after calling builtin instructions.
Rest are xwam changes due to compiler changes.

b64_dec now accepts list(Var) as output spec

added a check that inpput to b64_dec must be a string.
Fixed a typo in an abort in base64.P

Changed some imports from usermod to correct places.

reconfigured and recompiled for windows.
Also updated xwam files that were in need

added base64.* for base64 encoding/decoding
curl package: headers, put, post
fixed latex bugs in manual2 - viewsys, persistent tables

returned tempfilename to before Teri's changes because her implementation is not equivalent

Fixed psc_mod builtin to return usermod-psc instead of 0.

Fixed a couple of erroneous imports: should not be from usermod.

Ditto of last message.