* Adds methods for copying raw data to the data field of Ethernet frames and
UDP packets. This is used in the port to wrap the higher-layer packet data
prepared by the contrib code with the additionally required headers before
sending it at a network session.
* Adds a method to cast raw data to an IPv4 packet. This is required in the
port in order to check values in stand-alone IP packets produced by the
contrib code before sending them at a network session.
* Adds methods for setting UDP ports given big endian port values without
having to convert to little endian in the app and then back to big endian in
the net lib.
Ref #4397