util.prosodyctl.check: Check for server-to-server Direct TLS records

mod_s2s: Rename Direct TLS listener 's2s_direct_tls' Following the style of other options like (c2s|s2s)_require_encryption, s2s_secure_auth etc.

mod_s2s: Add a Direct TLS listener Mirroring the c2s 'direct_tls'. Naming things is hard. direct_tls_s2s_ports = { 5269+1 }

mod_s2s: Handle connections having TLS from the start This could be done with multiplexing, or a future additional port definition.

mod_s2s: Factor out procedure for newly encrypted sessions Goal is to call this if the connection is using Direct TLS, either via multiplexing or a future Direct TLS S2S port.

mod_bosh,mod_websocket: Make into global-shared modules (...again) Global modules aren't quite considered loaded onto hosts, which causes confusion in some cases. They are also reported in the log as being served on http://*:5280/foo which is also a bit confusing, and can't be clicked. Global modules also have to have their paths configured in the global section, which could be confusing and unexpected. This global+shared method should be the best of both worlds.

mod_c2s,mod_s2s: Indicate stanza size violation with condition from XEP-0205 (thanks mjk)

mod_pubsub: Move reversal of item order in <items> Examples in XEP-0060 suggest that items should be listed in chronological order, but we get them from the archive in reverse order. However when requesting specific items by id the results keep that order and we don't want to flip it again. At some point it would likely be best to use the archive API directly instead of this util.cache-compatible wrapper.

mod_pubsub: Add support for limiting result size #1608

util.pubsub: Add support for limiting number of items to retrieve Hopefully this will eventually be upgraded to RSM, which is why the argument is called 'resultspec' and is a table.