TYRUS-375: Buffer overflow during HTTP Response parsing (jdk client container)
	-response size is still limited, but better error handling added
TYRUS-376: client container automatically releases resources after the last connection has been closed
	- client container creates an executor service and a scheduled executor service if their container-managed
		varians are not found. These created executors were not shut down after the client has finished.
Test fixed -> 2 servers were bound to the same port
Test fixed -> 2 endpoints with the same path
TYRUS-367: Provide a way how to get low-level info about the session
TYRUS-367: review, refactoring (naming, error reporting, TyrusSession and test modification)
TYRUS-367: UtilsTest.validateConnectionProperties fixes + tests.
temporary ignoring IPv6EchoTest
trying to stabilize tests