Feature 1255: modification in sql queries

- manage random function
    - manage regex syntax
    - manage quote (single instead of double)
    - manage interval

git-svn-id: http://piwigo.org/svn/trunk@4367 68402e56-0260-453c-a942-63ccdbb3a9ee

include/calendar_monthly.class.php

@@ -347,7 +347,7 @@ SELECT id, file,tn_ext,path, width, height, DAYOFWEEK('.$this->date_field.')-1 a
     $query.= $this->inner_sql;
     $query.= $this->get_date_where();
     $query.= '
-  ORDER BY RAND()
+  ORDER BY '.DB_RANDOM_FUNCTION.'()
   LIMIT 1';
     unset ( $page['chronology_date'][CDAY] );