[Halld-offline] PHOTOS radiative correction package

[Sean Dobbs]

Hi Eugene,

As we discussed, the standard radiative correction package that we
used at CLEO (and is generally widely used) for dilepton decays, etc.
that I am adding to our event generator is called PHOTOS.

You can find a version of the package at the following link (it is
packaged with several other event generators):
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwasm.web.cern.ch%2Fwasm%2Ff77.html&data=02%7C01%7Challd-offline%40jlab.org%7C4664886606e54c2f41a908d680a6acd5%7Cb4d7ee1f4fb34f0690372b5b522042ab%7C1%7C0%7C636837850693905203&sdata=mi53zCOGfdr7AsIEIBpqdmLpwKsom3S40heyw7y85Go%3D&reserved=0

A C++ version can also be found
https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpiters.web.cern.ch%2Fpiters%2FMC%2Fphotos%2F&data=02%7C01%7Challd-offline%40jlab.org%7C4664886606e54c2f41a908d680a6acd5%7Cb4d7ee1f4fb34f0690372b5b522042ab%7C1%7C0%7C636837850693905203&sdata=crv2lT1HaA8Ov6WlWHFoqlP9Znz6xDiMrVxRdx8oTHI%3D&reserved=0

I'll send some comparisons soon.

Cheers,
Sean

PS.  I'm cc'ing this info to the software list at Beni's request.