need to reevaluate the tolerances

[zingale]

We ask for species to be evolved to a tolerance of 1.d-12 (in integration/_parameters).

This is pretty tight. We need to check whether it can be relaxed. We can relax on a network-by-network basis (using priorities in the _parameter files).

It seems that the original aprox13 and aprox19 networks used tolerances of 1.e-6

[zingale]

note also that the BS integrator has only a single tolerance -- it takes the max of all the tolerances:

    bs % atol(:) = 0.d0                                                         
    bs % rtol(:) = max(rtol_spec, rtol_temp, rtol_enuc)                         

[zingale]

the way to properly do this is to look at convergence of the results as we tighten the tolerances for each burner / integrator.

[zingale]

there is some thought on this in the wdmerger II paper. It seems that 1.e-8 should be okay...

[zingale]

I think that @abigailbishop largely has done this. We should add some plots to the user's guide

[abigailbishop]

I can do that.

[zingale]

I think we've mostly addressed this now.