Add creation_address column to users

This is a properly typed and indexed column that is intended
to replace creation_ip to allow fast queries.

app/controllers/users_controller.rb

@@ -267,6 +267,7 @@ class UsersController < ApplicationController
     current_user.data_public = true
     current_user.description = "" if current_user.description.nil?
     current_user.creation_ip = request.remote_ip
+    current_user.creation_address = request.remote_ip
     current_user.languages = http_accept_language.user_preferred_languages
     current_user.terms_agreed = Time.now.utc
     current_user.tou_agreed = Time.now.utc

app/models/user.rb

@@ -33,9 +33,11 @@
 #  tou_agreed           :datetime
 #  diary_comments_count :integer          default(0)
 #  note_comments_count  :integer          default(0)
+#  creation_address     :inet
 #
 # Indexes
 #
+#  index_users_on_creation_address   (creation_address) USING gist
 #  users_auth_idx                    (auth_provider,auth_uid) UNIQUE
 #  users_display_name_canonical_idx  (lower(NORMALIZE(display_name, NFKC)))
 #  users_display_name_idx            (display_name) UNIQUE