server4: Respect listen address

NewIPv4UDPConn doesn't support listening on a specific address, only on
the wildcard address. This extends it to allow listening on an address,
and at the same time homogenizes the function signature with the
NewIPv6UDPConn server6 equivalent. It modifies NewServer() to pass the
full address given to it instead of just the port as well

Note that listening on a non-wildcard interface is seldom useful as the
socket won't receive broadcasts, so it is useless in a direct-attached
server. It can be useful in a server only used behind relays

This breaks API compatibility for NewIPv4UDPConn, which as far as I know
nobody uses (yet)

Signed-off-by: Anatole Denis <natolumin@unverle.fr>

0 files changed, 0 insertions, 0 deletions