implement timeout for entry, adapt to stupid time window
estimated average calculation
adapt to correct concept: not snapshot of workload, but every response
time reflect an actual request to server, as an attribute of this
request. Although, it's still doing real-time monitoring rather than
keeping the history for delt_t.
First task seems to be done!!!
Merge branch 'development' of https://github.com/guoger/EP2300 into development