New termsofservice app

Slightly more reusable, slighly less history
Add TOS model and clean up

TODO: TOS model still needs a pre_save signal to create diff
Create diff on TOS save.

At some point we can display this to the user.
Index view for "Help"
New index page for help

Automagically grey out TOS and Who if there are no objects there
Only autodiscover admin URLs when we want to enable the admin site
Soon.

This app can be deployed without having to worry about not having ToS or staff bio

[skip ci]
Link anon users to Help too

[skip ci]
Merge branch 'new-tos'

Closes #5