It defines a ws_in4_addr type, which is intended to hold IPv4 addresses
in network byte order, and some macros to test for IPv4 addresses in the
local network control block and multicast IPv4 addresses.
Use those macros in places where dissectors had their own code for that
purpose.
Change-Id: I4252b410e37207157be85119a332e2a6913b332f
Reviewed-on: https://code.wireshark.org/review/24178
Reviewed-by: Guy Harris <guy@alum.mit.edu>
Guy Harris