Add support for SF

[tdooner]

I live in SF now and want to follow the election here.

Here's how to I'll plan to add support:

• Remove hardcoding of "COAK" Netfile agency and replace with a table that stores agencies
• Create database columns to keep track of which subscribers are subscribed to which Netfile agencies
• Create database columns to keep track of which filings came from which Netfile agencies
• Update alert mailer to only show subscribers the filings from their agency
• Download SFO and COAK agencies nightly
• Subscribe myself to it for some time
• Remove OpenDisclosure links when viewing a non-COAK agency
• Update copy for anything that is Oakland specific
• Release to a small set of beta users
• Create a new way to subscribe via the homepage
• Add support for custom SF form types

Future work:

• Unified subscription between the two agencies?