Escape table names in StructuralDBElement

Fixes issue #66

lib/Base/StructuralDBElement.php

@@ -433,8 +433,8 @@ public function getSubelements($recursive)
         if (! is_array($this->subelements)) {
             $this->subelements = array();
 
-            $query_data = $this->database->query('SELECT * FROM ' . $this->tablename .
-                ' WHERE parent_id <=> ? ORDER BY name ASC', array($this->getID()));
+            $query_data = $this->database->query('SELECT * FROM `' . $this->tablename .
+                '` WHERE parent_id <=> ? ORDER BY name ASC', array($this->getID()));
 
             $class = get_class($this);
             foreach ($query_data as $row) {
@@ -741,8 +741,8 @@ public static function checkValuesValidity(&$database, &$current_user, &$log, &$
         // we search for an element with the same name and parent ID, there shouldn't be one!
         $id = ($is_new) ? -1 : $values['id'];
         $query_data = $database->query(
-            'SELECT * FROM '. $parent_element->getTablename() .
-            ' WHERE name=? AND parent_id <=> ? AND id<>?',
+            'SELECT * FROM `'. $parent_element->getTablename() .
+            '` WHERE name=? AND parent_id <=> ? AND id<>?',
             array($values['name'], $values['parent_id'], $id)
         );
         if (count($query_data) > 0) {