Changed rails_admin dependency to active admin.
Removed rails_admin initializer.
Removed rails admin routes.
Dropped rails admin histories table.
Generated active_admin install without users.
Configured active_admin helper methods and paths.
Disable active_admin comments.
Updated admin link to use active_admin named route.
Removed rails_admin_controller check.
Installed active_admin/cancan integration gem.
Updated to skip authorization on admin urls when user is an admin.
Added user as an active admin resource.
Removed note/comment migrations.
Monkey patched active admin's resource controller to work with strong parameters.
Fixed active admin logout link method.
Fixed admin link condition.
Tweaked user index page.
Added systems to admin interface.
Added statuses to admin interface.
Dropped boolean filter on users (availability); doesn't work right just yet.
Simplified system filters.
Added responsibility editing to system edit screen. Fixes #35.