Translatable (and filterable) footer text

git-svn-id: http://yourls.googlecode.com/svn@856 12232710-3e20-11de-b438-597f59cd7555
More translation readyness

git-svn-id: http://yourls.googlecode.com/svn@857 12232710-3e20-11de-b438-597f59cd7555