Additional information on newer templates.

[jackcturner]

Would it be possible to get further information on how some of the newer template sets, particularly tweak_fsps, were constructed?

It would be useful to know the assumed metallicity, dust attenuation law, etc, so they can be used consistently.

Additionally it would be great if the nature of the values in the SFH file could be clarified. When plotting what must be the SFR against time based on the given units (kg/yr) in units M_sun/Gyr, the values are identical to the accompanying plot labelled as sSFR/Gyr. I'm unable to make sense of this.