French translation
Fix issue_id param when new issue

With redmine 2.2.1 when creating a new issue, it defines issue_id param to the 'null' string
search_issues_controller check params[:issue_id].blank?
Merge pull request #31 from xavier-calland/issue_id_param

Fix issue_id param when new issue
Merge pull request #32 from xavier-calland/locale_fr

French translation
Fixed possible name resolution problem.