XSB Src (SVN)-old

Update/improve CR's groundedness mode checker/inferencer and make all compiler modules compliant. Also update the Makefile so remaking the compiler invokes the mode checker/inferencer.

Added non-opt compile around a cryptic warning.

Increased maximum number of indexes allowed on a predicate, and issue warning if max is exceeded in an assert.

Fixed dynamic import (builtin) to handle quoted module names (and so handle non-parameterized modules). Also fixed innocuous typo in loader.

Fixed some code rot for the MT engine.

Generalized the way the .xsb/ dir is determined. Now:

o use the value of environment $XSB_USER_AUXDIR if defined and not ""
o use $HOME/.xsb, if HOME is defined
o use $USERHOME/.xsb, if USERHOME ...
o use XSBinstalldir/.xsb

This generalization is needed when XSB is used by a servlet. Eg, tomcat runs as a nologin user and its $HOME is owned by root. So, no way to run XSB this way. With $XSB_USER_AUXDIR, one can point to a dir owned by user 'tomcat'.
Dunno how this kind of services are done on windoze, but probably useful there as well.

fixed some incorrect comments
also incorrect refs to .xsbrc in the manual

Created a new p2p_attvar to replace p2p_arg(_,0)

Add simple predicate to gensym to help logging. Slightly improved performance of unnumbervars, which is heavily used in prolog_db.

Comment out unnecessary import to avoid warning.