Add support for suspended and confirmed users

Replace the existing "active" and "visible" with an enumerated status
that allows for extra cases. Currently we have "suspended" for users
who hve triggered the spam detector and "confirmed" for users that have
triggered the detector but have been confirmed as vald by an admin.

db/migrate/051_add_status_to_user.rb

@@ -0,0 +1,29 @@
+require 'lib/migrate'
+
+class AddStatusToUser < ActiveRecord::Migration
+  def self.up
+    create_enumeration :user_status_enum, ["pending","active","confirmed","suspended","deleted"]
+
+    add_column :users, :status, :user_status_enum, :null => false, :default => "pending"
+
+    User.update_all("status = 'deleted'", { :visible => false })
+    User.update_all("status = 'pending'", { :visible => true, :active => 0 })
+    User.update_all("status = 'active'", { :visible => true, :active => 1 })
+
+    remove_column :users, :active
+    remove_column :users, :visible
+  end
+
+  def self.down
+    add_column :users, :visible, :boolean, :default => true, :null => false
+    add_column :users, :active, :integer, :default => 0, :null => false
+
+    User.update_all("visible = true, active = 1", { :status => "active" })
+    User.update_all("visible = true, active = 0", { :status => "pending" })
+    User.update_all("visible = false, active = 1", { :status => "deleted" })
+
+    remove_column :users, :status
+
+    drop_enumeration :user_status_enum
+  end
+end