* Add a ReportFilter class
* Add reports and targeted_reports relationships to Account
* Use ReportFilter from admin/reports controller
* Link to admin/reports filtered views from admin account show view
* Add indexes to reports.account_id and reports.target_account_id
* 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