A few changes to improve debuggability:
1) We now print the stack trace that created an orphan thread, in addition to the current stack trace.
2) we add the ability for a connector to tell the integration runner to not care about certain threads (by adding a thread filter)
3) We change the log of connector containers to include the name of the test that created it (usually each test will create and close a container)
4) We also log when the timeout timer gets triggered, to try to understand why some tests are still taking way more time than their timeout should allow
Another change that was initially in there but has been removed and might be worth thinking about:
Today, only Write checks for live threads on shutdown. We might want to do that for other operations as well
