Integrate SolveBio Clinvar into variant details (and condensed view)

Adds a requirement for the SolveBio Python client, which contains a small wrapper for Django apps. The Django module allows SolveBio datasets to be locally aliased, so that a query to "clinvar" will route to "clinvar/0.0.2/clinvar" in SolveBio. The query is integrated into the variant API resource and filters clinvar by chromosomal position, gene symbol, and HGVS notation.

Dataset aliases can be set in a Django setting (`SOLVEBIO_DATASETS`) and via the Django Admin (see below). The Django setting overrides the values in the database.

![screen shot 2014-03-25 at 3 24 08 pm](https://f.cloud.github.com/assets/7460/2517286/7315b97c-b457-11e3-9e4e-4221d9a5144e.png)