make smooth, add max pending count for per client

[wsky]

for balance

make server cpu/throughput smooth

• max total buffer
• max per client pending count
• max flush count per client
• worker count
• state build idle
• ping interval

for single client:

• max per client pending count
• max flush count per client adjust them will make client got more bandwidth and high Priority

[wsky]

whatever client send faster, per client cost should smooth, keep total throughput