Show/hide annotations in sidebar.

Includes:
* Showing and hiding using jquery after backbone render.
* This is untested. Feature specs using capybara are not playing well.
* Sorts the annotations by position in the document.
Basic apartment integration
Database cleaner config to work correctly with apartment schemas
Auto-create schemas when a tenant is created
Better setup and seeding tooling
AdminUsers are "global" across all tenants
Ensure that the current tenant is enqueued as part of job enqueueing
Switch tenancy when running DelayedJobs, keeping the queue in the public schema
Customize devise mailers to use urls pulled off Tenant#subdomain
Interpolate the tenant name into the path
Add basic ActiveAdmin tenant config
Switch to a Generic elevator that will default to Public