We used to have one global socket, use one per transaction instead. This
has the side-effect of giving us a random UDP port per transaction, and
hence increasing the entropy and making cache poisoining significantly
harder to achieve.
We still reuse the same port number for packets belonging to the same
transaction (resent packets).
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
Tom Gundersen