negative fluxes getting clipped

[saurabhwjha]

the combine step eliminates fluxes < 0, but faint objects may have noisy data there that shouldn’t be clipped; can we set the chip gap pedestal to be -5000 or something rather than 0, and then set the combine lthreshold to be -4999?

[cmccully]

That is a good idea. I will take a look (or feel free to fix it with a pull request).

[saurabhwjha]

I think I can do it; I was just seeing if you thought it might cause other problems.