Allow a special ODBL message to be displayed at login

app/controllers/user_controller.rb

@@ -282,6 +282,8 @@ class UserController < ApplicationController
       else
         password_authentication(params[:username], params[:password])
       end
+    elsif params[:notice]
+      flash.now[:notice] = t "user.login.notice_#{params[:notice]}"
     elsif flash[:notice].nil?
       flash.now[:notice] =  t 'user.login.notice'
     end

config/locales/en.yml

@@ -1545,6 +1545,7 @@ en:
       webmaster: webmaster
       auth failure: "Sorry, could not log in with those details."
       notice: "<a href=\"http://www.osmfoundation.org/wiki/License/We_Are_Changing_The_License\">Find out more about OpenStreetMap's upcoming license change</a> (<a href=\"http://wiki.openstreetmap.org/wiki/ODbL/We_Are_Changing_The_License\">translations</a>) (<a href=\"http://wiki.openstreetmap.org/wiki/Talk:ODbL/Upcoming\">discussion</a>)"
+      notice_terms: "OpenStreetMap is moving to a new licence on 1st April 2012. It's just as open as our current one, but the legal bits are much better suited to our map database. We'd love to keep your contributions in OpenStreetMap, but we can only do so if you agree to let us distribute them under the new licence. Otherwise, we'll have to remove them from the database.<br /><br />Please log in, then take a few seconds to review and accept the new terms. Thank you!"
       openid missing provider: "Sorry, could not contact your OpenID provider"
       openid invalid: "Sorry, your OpenID seems to be malformed"
       openid_logo_alt: "Log in with an OpenID"