ER_LOCK_WAIT_TIMEOUT".

The problem was that after changes caused by fix bug 14188793 "DEADLOCK
CAUSED BY ALTER TABLE DOEN'T CLEAR STATUS OF ROLLBACKED TRANSACTION"/
bug 17054007 "TRANSACTION IS NOT FULLY ROLLED BACK IN CASE OF INNODB
DEADLOCK implicit rollback of transaction which occurred on ER_LOCK_DEADLOCK
(and ER_LOCK_WAIT_TIMEOUT if innodb_rollback_on_timeout option was set)
didn't start new transaction in @@autocommit=1 mode.

Such behavior although consistent with behavior of explicit ROLLBACK has
broken expectations of users and backward compatibility assumptions.

This patch fixes problem by reverting to starting new transaction
in 5.5/5.6.

The plan is to keep new behavior in trunk so the code change from this
patch is to be null-merged there.