Fix discrepancy between goal and path goal scaling

Deviating from what I said in #1046 (closed), I just made it one single commit (that will become part of the 2.2 release as a fix). It does add a new goal programming option which can be argued to be a new feature (and therefore violating the "feature freeze"), but while implementing this I felt that the feature was strongly connected (if not part of) to the fix.