[santacruzgalaxy-list] Grackle proposal

[Nick Gnedin]

That proposal is meant as a first step, let's all modify it so that it 
fits everyone's needs. What I wrote is what *** I think *** how cooling 
should be implemented in a hydro code, others will surely think differently.

> I'm not sure this is an
> improvement over the existing system?

It did not meant to be a replacement for the existing system, if the 
existing system fits the requirement, then the problem is already solved.