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/helpers/application_helper.rb

@@ -70,8 +70,8 @@ module ApplicationHelper
   
   def format_date(date)
     return nil unless date
-    @date_format_setting ||= Setting.date_format.to_i
-    @date_format_setting == 0 ? l_date(date) : date.strftime("%Y-%m-%d")
+    @date_format ||= (Setting.date_format.to_i == 0 ? l(:general_fmt_date) : date.strftime("%Y-%m-%d"))
+    date.strftime(@date_format)
   end
   
   def format_time(time)