Performance improvement on calendar and gantt (about 45% on gantt for large number of issues).

Partial issues/_tooltip is replaced by an helper and some translated strings are now cached.

git-svn-id: http://redmine.rubyforge.org/svn/trunk@794 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/controllers/projects_controller.rb

@@ -34,6 +34,7 @@ class ProjectsController < ApplicationController
   include CustomFieldsHelper   
   helper :ifpdf
   include IfpdfHelper
+  helper :issues
   helper IssuesHelper
   helper :queries
   include QueriesHelper

app/controllers/timelog_controller.rb

@@ -21,6 +21,7 @@ class TimelogController < ApplicationController
 
   helper :sort
   include SortHelper
+  helper :issues
   
   def report
     @available_criterias = { 'version' => {:sql => "#{Issue.table_name}.fixed_version_id",