This is a redo for 5.5
Added 'innodb_file_format_max' as variable to ignore change to.
Tests that had to restore this amended
Two tests assumed it to be Antelope, make sure these run on a freshly
started server
With this change, the index prefix column length lifted from 767 bytes
to 3072 bytes if "innodb_large_prefix" is set to "true".
rb://603 approved by Marko