clean NewMessageListener related implement,with ui improve
prepare for history poll query type.if browser refresh triggered,any js
stored value is cleared,so we need this query type to load history
messages(newest)
client user REFRESH and HISTORY query to identify action ,so no need to
clean MessageListener when user has session but not logined
improve to poll front ui
try to fix fast poll trigger bug.do not force wake up suspended
continuation when reseting to new Continuation. or we meet a
trigger-bug:
since one listener only wait on one continuation
overlap request-session 1 trigger  request-session 2 flush
request-session2 received messages and immediately do another overlap
(overlap request-session 1).with this patch, too fast poll request will 
be rejected and return immediately,previous waited one is reserved
(except that reset one is NULL,means flush cached messages)
add unread message popup (not complete)