[repo] Add a publish/subscribe mechanism for inter-instance communication using zmq
Each repo can have a publishing and any number of subscribing sockets
whose addresses are specified in the instance's configuration. An
application or cube can subscribe to some 'topics', and give a callback
that gets called when a message matching that topic is received.
As a proof of concept, this introduces a hook to clean up the caches
associated with the repository when an entity is deleted.
A subscription is added using Repository::zmq::add_subscription;
the callback receives a list representing the received multi-part
message as argument (the first element of the message is its topic).
#! /bin/sh -e
case "$1" in
purge)
rm -rf /etc/cubicweb.d/
rm -rf /var/log/cubicweb/
rm -rf /var/lib/cubicweb/
;;
esac
#DEBHELPER#
exit 0