Comment 5 for bug 909376

Issues with the test, in no particular order:
1) tries to check everything while losing the regression itself, making it hard to inspect the output.
2) Everything goes to the same log file and then is grepped for total occurrences of some strings. Thus if Last_errno: ^0 goes somewhere else by error, the test passes.
3) The 2nd and 3rd sub-tests are virtually identical.
4) Home-brewn include/wait_until_count_sessions.inc replacement.
5) have_innodb instead of have_innodb_plugin check.
6) Errno grep pattern for non-zero error case matches Last_errno: všašeakjl, does not match Last_errno: 10.