Move to relational vcf storage and backend queries

This is The Great Migration. 

This PR introduces a schema for and code around loading VCFs into a PostgreSQL database, as well as querying those records via a JSON RESTful API. 

Much work needs to be done to fully integrate this and patch up the code touched by the change (hint: most of it). 

1. Charts and the Karyogram on the examine page.
2. Clean up SQL construction
    1. Remove or update models.py
    2. handle possible injection issues (use SQLAlchemy more here?)
3. Clean up views.py
4. Improve validations.py & associated field names. 
5. Explore: Serialize records and send them to client after initial load. 
6. Performance optimizations.
7. Robust workers.
8. Fix concordance worker & visualization (need a new table in the DB).
9. Fix/remove scorer worker.
10. TESTS!
11. Variant sorting tabs need to be fixed.

And probably some more. Will be adding these as issues.
I prefer it, because the bookkeeping is easier. Just increment the page, and let the server handle the rest. It also mirrors the underlying SQL, not that that's a great reason, but hey, I'm drinking a lot of coffee today.

I think this will probably soon be changed to just send all records over to the client, anyway.