eadsax used from sul-dlss fork

[atz]

Looks like a combination of changes that might be acceptable upstream and possible incompatible customizations, but not a ton of divergence:

https://github.com/jronallo/eadsax/network

Do we want to maintain this fork? If so, we should probably still publish the gem as normal (to something like eadsax-sul). If not, we should submit PRs to jronallo.