Update some docblocks

common.php

@@ -78,7 +78,7 @@ function db_filter($array, $index)
  * Connection function
  *
  * @param string|object|array $params
- * @return Query_Builder
+ * @return Query\Query_Builder|null
  */
 function Query($params = '')
 {

core/abstract/abstract_driver.php

@@ -92,8 +92,8 @@ abstract class Abstract_Driver extends \PDO implements Driver_Interface {
 	 *
 	 * @param string $sql
 	 * @param array $data
-	 * @return PDOStatement PDOStatement / FALSE
-	 * @throws InvalidArgumentException
+	 * @return \PDOStatement | FALSE
+	 * @throws \InvalidArgumentException
 	 */
 	public function prepare_query($sql, $data)
 	{
@@ -124,7 +124,7 @@ abstract class Abstract_Driver extends \PDO implements Driver_Interface {
 	 *
 	 * @param string $sql
 	 * @param array $params
-	 * @return PDOStatement
+	 * @return \PDOStatement
 	 */
 	public function prepare_execute($sql, $params)
 	{

core/interfaces/query_builder_interface.php

@@ -416,7 +416,7 @@ interface Query_Builder_Interface {
 	 *
 	 * @param string $table
 	 * @param array $data
-	 * @return PDOStatement
+	 * @return \PDOStatement|null
 	 */
 	public function insert_batch($table, $data=array());