keep-alive

this example shows the usage of QHttp and keep-alive connections.

##usage

$xbin/> ./keepalive --help

server mode:

$xbin/> ./keepalive server --port 8090

client mode:

$xbin/> ./keepalive client -p 8090 --count 1000

transimts 1000 packets in a single HTTP connection, which is definitly a lot more efficient than making 1000 connection.