net: remove use of arguments in Server constructor

The current implementation uses the arguments object in the Server()
constructor. Since both arguments to Server() are optional, there was a
high likelihood of accessing a non-existent element in arguments, which
carries a performance overhead. This commit replaces the arguments
object with named arguments.

Reviewed-by: Trevor Norris <trev.norris@gmail.com>

Conflicts:
	lib/net.js