wrong calculation of total inverse mass

[cosfer65]

in function void ParticleContact::resolveInterpenetration(real duration) (pcontacts.cpp around line 100)
you calculate total inverse mass like this
// The movement of each object is based on their inverse mass, so
// total that.
real totalInverseMass = particle[0]->getInverseMass();
if (particle[1]) totalInverseMass += particle[1]->getInverseMass();

I think this is mathematically wrong since 1/mass1 + 1/mass2 is not the same as 1/(mass1+mass2) as I think you mean. Browsing through the code I saw the same calculation in a number of points.

[LucasCampos]

This seems to be related to issue #13