[WIP] ELBv2 Support

[eherot]

This adds support for ELBv2. It's a work in progress. Work has actually stalled for the moment because we haven't been making a lot of ELBs recently, but I do want people to be able to use it/contribute in the mean time.

[nickpetrovic]

@eherot any progress on this? need any help?

[jeffbyrnes]

@nickptrvc please feel free to run with it! @eherot & I both moved on from @evertrue to other companies, and are unlikely to come back to this anytime soon.