the new timetravel.c,
new timetravel.README (cut from spi/README and modified),
modified timetravel.sql.in
and modified timetravel.example.

Features:
- optionally 3 parameter for insert/update/delete user name

- work with CREATE UNIQUE INDEX ixxx on table xxx
(unique_field,time_off);
    (the  original version was work with unique index on 6.5.0-6.5.3,
and not work on 7.3.2,7.3.3)
     (before 6.5.0 and between 6.5.3 and 7.3.2 I dont know)

- get_timetravel(tablename) function for check timetravel-status.

- timetravel trigger not change  oid of the active record. (it is not a
good feature, because the  old version is automatice prevent the paralel
update with "where oid=nnn")

B?jthe Zolt?n