Previously, invoking HttpServletRequest#changeSessionId on session backed by HazelcastSessionRepository generated generated invalid session destroyed and session created events. This was due to use of IMap#remove and IMap#set when handling the change session id.
This commit improves change session id handling to prevent publishing invalid events by using IMap#delete instead of IMap#remove and keeping track of originally assigned session id.
Closes gh-1077
8dac35cf73