#6969 - MODS export

Addition of MODS bulk export, addition of new MODS export fields, and addition of a site base URL DB setting.
I actually like this way of doing else statements better than what we usually use...

if (...)
{
}
else
{
}

But we should be consistent across the code base I think. I guess it's sort of moot at this point since I've seen a few different if/else styles :(