- put in a new admin_multi_view:allows admins to change on the fly language/theme and view gallery as guest (useful for developers and just to show a 'new' way of using plugins)
- removed some warnings from history.php and increased table width to 99%
- remove unused admin language strings
git-svn-id: http://piwigo.org/svn/trunk@1821 68402e56-0260-453c-a942-63ccdbb3a9ee
