First stab at making iNat an OAuth2 provider with doorkeeper.
Added owner to oauth apps, custom controller.
Started adding API specs.
Ensured that HTTP Basic still works, cleaned up aouth checks.
Added custom assertion oauth2 flow.
Added attempt at bounce authorizations. Pretty experimental.
Merge branch 'oauth'

Conflicts:
	db/structure.sql
Bugfix: obs/index doesn't need oauth protection.