After-review changes

* remove redundant code
* fix tests
* move declarations and defines where they belong

include/my_time.h

@@ -171,6 +171,10 @@ static inline my_bool validate_timestamp_range(const MYSQL_TIME *t)
   return TRUE;
 }
 
+/* Can't include mysqld_error.h, it needs mysys to build, thus hardcode 2 error values here. */
+#define ER_WARN_DATA_OUT_OF_RANGE 1264
+#define ER_WARN_INVALID_TIMESTAMP 1299
+
 my_time_t 
 my_system_gmt_sec(const MYSQL_TIME *t, long *my_timezone, uint *error_code);