(Bug #36285, rb://9).
innodb-index.test, innodb-index.result: Set innodb_lock_wait_timeout as
a session variable instead of relying on the global value.
innodb-index-master.opt: Remove.
innodb-timeout.test: Test that setting the innodb_lock_wait_timeout
works as advertised.
thd_lock_wait_timeout(): New function, to retrieve the lock wait timeout
for a given MySQL client connection (thd), or the global value (thd==NULL).
srv_lock_wait_timeout, innobase_lock_wait_timeout: Remove.
Replace MYSQL_SYSVAR_LONG(lock_wait_timeout)
with MYSQL_THDVAR_ULONG(lock_wait_timeout).
