makes continuation has timeout
refactor LoginServletTest to do more code share
add PollServlet simple test
add PollServlet to EmbeddedHttpServer
refactor QueryMessage family servlet,fix PollServlet re-parse request
twice bug

since Continuation resume gives a request with input stream already
readed ,we must store parsed result into continuation,then get it back
fix alias parameter in BaseListener.resetContinuation
add PollServlet long poll test
update ClientUserInfo.equals
add same(IgnoreUser)IdBytes compare method to user and message, for
compare between http read back and runtime generated ones
add PollServlet should polled new message test
use UniqueObject .dataStore to do db operator
use UnsavedMessageQueue to do new message save in MessageService
refactor implement and add some comment
try to implement listener switch
more PollServlet test