Comment 7 for bug 493102

OK, my list of weird people has 2 items now:

* gomechanicians
* contact law freaks

Seriously, though (and with all due respect), for me the reference is continuum mechanics; in structural engineering (presumably in mechanical engineering as well), in FEM etc etc, outer normal is used, leading to tension having positive sign. I am happy I already persuaded Bruno.

For ht work to be done on this: since the ScGeom-based laws use shearForce in the incremental formulation, all the increments must have signs changed. I think it doesn't need more than a few hours of attentive code walkthrough (by someone who is familiar with the code) and some testing.