util.prosodyctl: check: warn about unreferenced components, suggest disco_items

util.prosodyctl: Warn about enabled public registration in 'check config'

util.poll: Add support for the poll() API Might be better than select(), more portable than epoll.

util.poll: Expose API (epoll or select) used Could he handy to know for debugging or decisions

util.poll: Restructure to make adding additional system APIs easier

make: Split up install targets to allow different subset The prosody-trunk nightly packages currently use the Debian dh-lua framework to install core/, net/ and util/ into Lua-versioned directory trees, while plugins and executables should still be installed like before.

core.portmanager: Fix traceback on attempt to get non-existent service If there's no such interface:port then `data` is nil and `data.service` errors.

mod_c2s,mod_s2s: Fix error on shutdown (Thanks Martin) Since there are two calls to done() that can happen, if the timing is right (or wrong) both can happen, which previously triggered an error.

util.async: Optionally allow too many 'done' callbacks Sometimes, like in mod_c2s and mod_s2s during shutdown, all you want is to wait for the first done() and not complicate things.

mod_c2s,mod_s2s: Wrap callback to improve tracebacks Should make traces point here instead of timer dispatch, making debugging easier