Dial: addr should be in the form of host:port.

DialWithRawAddr is intended for use by users implementing a local socks proxy.

NewCipher creates a cipher that can be used in Dial() etc.

NewLeakyBuf creates a leaky buffer which can hold at most n buffer, each with bufSize bytes.

PipeThenClose copies data from src to dst, closes dst when done.

UpdateConfig: Useful for command line to override options specified in config file Debug is not updated.