added a setting option to set max number of issues in export

git-svn-id: http://redmine.rubyforge.org/svn/trunk@234 e93f8b46-1217-0410-a6f0-8f06a7374b81

lang/en.yml

@@ -147,6 +147,7 @@ setting_default_language: Default language
 setting_login_required: Authent. required
 setting_self_registration: Self-registration enabled
 setting_attachment_max_size: Attachment max. size
+setting_issues_export_limit: Issues export limit
 setting_mail_from: Emission mail address
 setting_host_name: Host name
 setting_text_formatting: Text formatting