fix potential stat overflow

merge code from maock

remove rps in client

reset more flags in connect_to_host to handle reconnect case

set output_data_length to 0 in connect_to_host to handle reconnect case

bug fix: variable_present

sync code from maock: fix memory leak when connection is down

Merge pull request #9 from stxyang/main

enable "start_stats_thread" in lua interface "start_server"

sync code from maock: support non json payload; support statistic fil…

…e in embeded maock

multiple variables bug fix