Log Message:
Update chat/ejabberd to 17.03.

Major improvements
- New modular code allows to develop modules for a wide scope of
  functionalities without patching the core code such as C2S, S2S and
  router
- Now 'From' and 'To' arguments must be omitted in functions and
  structures related to routing
- Ejabberd used to store all in-memory shared data such as ACLs,
  proxy65, sessions, routes, clustering, etc in internal Mnesia
  database and this used to be hardcoded. With new API it's now possible
  to store such data in any database. However, currently only Mnesia
  backend is supported.
- Dynamic configuration reload allows to reload modules, database
  connections, listeners, ACLs and global options without restarting
  ejabberd
- Spam protection allows to block packets from non-subscribers
- S2S dialback is now an optional module

Developer
- tools/hook_deps.sh: checks hook dependencies
- tools/find-outdated-deps.pl: checks which dependences need update
- Mark as deprecated add/get_local/global_option config functions
- Change routing API

Core
- Fix some corner cases while re-reading RFC6120
- Attach IP metadata to every stanza received from stream
- Apply SASLprep before storing/converting passwords
- Send compressed in correct order
- Reset XML stream before sending SASL success
- Speedup features list when a lot of virtual hosts configured
- Fix s2s_dns_timeout issues
- Better handling of IPv6 domains
- Rename mod_sm -> mod_stream_mgmt
- Don't count resent stanzas
- Improve startup procedure, and log startup time
- Add more processes to supervision
- sm_sql: Avoid PID collisions

Admin
- Add 'supervisor' listening option
- Accept "add_commands: admin" in commands section
- Make sure that api_permissions always have "console commands"
  section
- Change name of pam dep from p1_pam to epam
- Improve compilation with rebar3
- Add TLS support for external components
- Specify "ExecReload" command in systemd unit
- Don't attempt to resolve _jabber._tcp SRV record
- Improve error reporting for forbidden servers
- mod_block_strangers: New module to block packets from
  non-subscribers
- mod_register: Report password change in the log
- Remove relict mod_service_log
- Remove unused mod_ip_blacklist
- Remove ejabberd_frontend_socket
- WebAdmin: improve formatting when showing erlang terms
- Import from Prosody: Fix import of SCRAM passwords, offline

API & Commands
- get_last now always returns tuple with UTC XEP-0082 and status
- Protect users from delete_old_users command using a fixed access
  rule
- Separate list of strings with \n for srg_get_info in mod_http_api
- Support non-JID lines in command create_rooms_file
- stop_all_connections now stops all s2s connections via supervisor
  calls
- Support scrammed passwords in ejabberdctl import_prosody

Configuration
- Provide example mod_http_api configuration with couple commands
- Clarify new modules usage in the example config
- Don't crash on malformed IP addresses
- Fix parsing of acl/access rules inside oauth sections of
  api_permissions

Config reload improvements
- Start/stop auth modules when host is added/deleted
- Improve modules start/stop procedures
- Check result of gen_mod:start/2 callback
- Improve reload_config admin command
- Invalidate access permissions on configuration reload
- Start/stop virtual hosts when reloading configuration file
- Reload modules when reloading configuration file
- Restart listeners on configuration reload
- Make sure all hooks are called with proper host

Databases
- Add missing NOT NULL restrictions in schemas
- Move archive tables into lite.sql for better comparison with other
  schemas
- Implement database backend interface for mod_proxy65
- Implement database backend interface for MUC, BOSH and auth_anonyous
- Implement database backend interface for ejabberd_router
- Propagate the TRANSACTION_TIMEOUT to pgsql driver

New XMPP stream behavior
- Reflect cyrsasl API changes in remaining code
- Improve return values in cyrsasl API
- More refactoring on session management
- Add xmpp_stream_out behavior and rewrite s2s/SM code
- Rewrite ejabberd_service to use new XMPP stream API

MAM & offline storage
- Make a message is not bounced if it's archived
- Archive message before delivering it to offline storage
- Include stanza ID with archived offline messages
- Add stanza-id to every archived message

PubSub
- Avoid orphan_item leak on affiliation/subscription removal
- Fix pubsub SQL schemas, add NOT NULL restrictions
- Fix last item cache for multiple hosts

Server to server
- Several improvements of S2S errors logging
- Resolve all addresses from SRV lookup
- Add s2s work-around for gmail.com