* ActivityPub migration procedure
Once one account is detected as going from OStatus to ActivityPub,
invalidate WebFinger cache for other accounts from the same domain
* Unsubscribe from PuSH updates once we receive an ActivityPub payload
* Re-subscribe to PuSH unless already unsubscribed, regardless of protocol
* Remove unused account_params method in admin/accounts controller
* Introduce AccountFilter to find accounts
* Use AccountFilter in admin/accounts controller
* Use more restful routes admin silence and suspension area
* Add admin/silences and admin/suspensions controllers
* Replace will_paginate with kaminari
* Use #page instead of #paginate in controllers
* Replace will_paginate.page_gap with pagination.truncate in i18n
* Customize kaminari views to match prior styles
* Set kaminari options to match prior behavior
* Replace will_paginate with paginate in views
* Add Admin::BaseController to wrap admin area
Extracts the setting of the `admin` layout and verifying that users are admins
to a common base class for the admin/ controllers.
* Add basic coverage for admin/reports and admin/settings controllers
