migrate all relevant code from p4p_for_isis repo

[kathryn-baker]

As this repo is based off a lot of code developed as part of the p4p_for_isis project we need to migrate any code that would be facility-agnostic into this repository so the logic can be consolidated here and only ISIS-specific code is required in p4p_for_isis.

[Monarda]

I think everything except for the documentation and Ajit's calc record and forward links code has now been migrated.