mod_pubsub_serverinfo: Detect existence of pub/sub node Instead of blindly trying to create the pub/sub node to publish items to, a service discovery query is performed to check if node creation is required. Added various bits of warn and debug logging, to give a user better feedback if and why something is failing.

# mod_tos

A very drafty module to implement some kind of Terms of Service acceptance
tool.

Currently, this only works with clients implementing this very drafty
protocol. The result of the experiments will be an update to the
[ToS ProtoXEP](https://xmpp.org/extensions/inbox/tos.html), with the goal
of acceptance.