bugfix#1025721 on launchpad

the origin tcprstat can only get the right stats on a server; if a host
act as both server and client; the tcprstat can not work correctly.
Now add a parameter mode , trying to tell it runing on a server or a
client
add multi-port support

we are running lots of instance on one host. To get RT of all, i hope
only one tcprstat can get rt individually
make output goto file

make output goto file rather than stdin/stdout/stderr , if paramters
specified.