new file:   grobner/README
fixed small bug. factored singularity code
	modified:   numerical/nintegrate.lisp
fix bugs in finding,including,excluding singularities
	modified:   numerical/nintegrate.lisp
	modified:   numerical/rtests/rtest_numerical.mac
clean up a little.
	modified:   numerical/nintegrate.lisp
	modified:   numerical/rtests/rtest_numerical.mac
	modified:   README
	modified:   buildall.mac