excluding /core/etc from copyright check
Session#getOpenSessions() now works on closed session

- consider session which needs to notify other sessions about its closure.
Grizzly 2.3.12
Introducing JDK client standalone bundle.

- TODO: rename tyrus-standalone-client to tyrus-standalone-client-grizzly?
removing unused imports
@OnMessage or messageHandler can consume supertype of decoded object.

- (arguments were wrongly swapped)
TYRUS-214 - Expose monitoring API/statistics - monitoring of message statistics has been added