Update templates for languages translation

 - add missing Smarty gettext missing blocks in jobs, client report, dashboard and header templates
Fix case of translated string in Jobs template

 - End Time => End time and Start Time => Start time
Update French translations
Update Changelog
Update all translation files

 - updated files header
 - updated files with new strings
Fix code for Back link in header template

 - removed Smarty gettext block from back link as it's not translated (inside a php block)
Fixed bug 0000151 - Period string not translated in Dashboard