Override cmp_postprocess for PolynomialFactors

[dpvc]

Don't do the cmp_postprocess() function for PolynomialFactors, since it tries to reduce the student answer, which can cause unwanted errors when singleFactors is set.

To test, use

loadMacros("contextPolynomialFactors.pl");
Context("PolynomialFactors")->flags->set(singleFactors => 1);
$f = Compute("-(x+1)(x-1)");
TEXT($f->cmp->evaluate("-(x+6)(x+2)")->{ans_message} || 'No Error');

Without the patch, you should get Only one factor or constant can be negated

With the patch, you should get No Error.

This comes originally from this forum post.

[mgage]

works