Log Message:
Update chat/ejabberd to 15.07.

Message Archive Management (XEP-0313)
- Add "complete" attribute to MAM final response
- Fix mod_mam compatibility with RSM
- Changed mam iq get to set as specified by XEP-0313 v0.3

Modules management
- Ensure config snippet is loaded at module installation
- Allow contribution to include .yml or .yaml config file
- Allow include of simple dependencies

Multi User Chat
- New API hook: muc_filter_packet
- Send notifications on MUC configuration changes
- Omit warning message regarding non-anonymous room
- During halt only shutdown MUC rooms on local node

Pubsub
- Allow migration of old pubsub items with old xmlelement structure in body
- Trigger PEP notifications on CAPS updates
- Check for node subscription of bare JID
- Flat is now the default plugin

Stream Management (XEP-0198)
- Increase timeout during resumption
- Increase default "max_ack_queue" value

ejabberd Client connection
- API change: user_send_packet is now a run_fold hook and pass the c2s State
  as a parameter. It was already the case in ejabberd 15.06, but it was not
  mentioned in the changelog, by mistake. So, now, you know :)

Admin
- Do not rely on behaviour info when doing config validation, so that it
  can work with ejabberd binary installers
- When passwords are scrammed, report check_password_hash cannot work
- Fix problem with merging values from multiple config files
- If local guide.html file not found, redirect to the online guide
- Support RTL page direction in WebAdmin for Hebrew
- configure.ac: add AC_CONFIG_MACRO_DIR and static AC_INIT

WebAdmin
- Don't crash web admin when displaying info about websocket using users

Installers