Bug#42003 tests missing the disconnect of connections <> default
second slice
Content:
1. wait_until_count_sessions.inc
   - One PB run of a test using this routine failed because
     5 seconds timeout were exceeded. Although I have some doubts
     if the assigned timeout was really too small, I increase the
     value to 10. We waste the additional 5 seconds only if the
     tests fails anyway.
   - Print the content of the PROCESSLIST if the poll routine fails
2. minor improvements of formatting
3. query_cache_notembedded:
   Activate the wait_until_count_sessions.inc routine which was
   unfortunately forgotten in the changeset before.