Estimated time recognizes improved time formats (#1092).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1361 e93f8b46-1217-0410-a6f0-8f06a7374b81

lib/redmine.rb

@@ -1,6 +1,7 @@
 require 'redmine/access_control'
 require 'redmine/menu_manager'
 require 'redmine/mime_type'
+require 'redmine/core_ext'
 require 'redmine/themes'
 require 'redmine/plugin'