ENT-600

PSA was monolothic, now split, with new features, like
a DB-backed partial pipeline. FB OAuth2 version also upped.

Partial pipelines don't get cleared except when necessary.
They persist for special cases like change of browser while
still mid-pipeline (i.e. email validation step).

Refactor, cleanup, and update of a lot of small things as well.

PLEASE NOTE the new `social_auth_partial` table.

When authenticating using an SAML IdP, gather additional user
data besides what is standard. Requires admin to input JSON
in settings to recognize the additional user data.

Cleaner, and keeps pylint happy

This reverts commit a020464a.

The python social auth SAML page returns a 500 response when accessed
without the 'idp' query param. It should redirect to the login page if
the param is missing.

SOL-1550