Add support for SF - Githubissues

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

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

[x] Remove hardcoding of "COAK" Netfile agency and replace with a table that stores agencies
[x] Create database columns to keep track of which subscribers are subscribed to which Netfile agencies
[x] Create database columns to keep track of which filings came from which Netfile agencies
[x] Update alert mailer to only show subscribers the filings from their agency
[x] Download SFO and COAK agencies nightly
[x] 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:

openoakland / disclosure-alert