jabberd-2.2.15 release

Next jabberd2 release is available.

The project had moved to GitHub, so this time get 2.2.15 release at:
https://github.com/Jabberd2/jabberd2/tarball/jabberd-2.2.15
https://github.com/Jabberd2/jabberd2/zipball/jabberd-2.2.15

and read: https://github.com/Jabberd2/jabberd2/blob/bc6a7a9cca/UPGRADE

This is a major feature release bringing the following changes:
(As you man notice most of the Apple ChatServer patches were merged.)

ChangeLog:
      * Implemented support for fake (PBX) sessions in SM
      * PBX integration priority setting support
      * Fix a crash that occurs when c2s connecting clients passed the
        defined connection limit
      * Log S2S retry timeout to main log
      * Do not log messages when not enabled or empty logfile configured
      * Define TRUE and FALSE in util.h
      * Merged ldapvcard improvements from Gentoo
      * Fail on not existing ldapfull user. Fixes Bug 931622
      * Added missing static keywords
      * [Apple ChatServer] Disable weak SSL ciphers
      * [Apple ChatServer] SQLite index on vCard owner
      * [Apple ChatServer] jabberd wrapper improvements
      * [Apple ChatServer] log_user category
      * [Apple ChatServer] Socket closing and component shutdown fixes
      * [Apple ChatServer] Support for DB query rate limitting
      * [Apple ChatServer] Support for multihomed IPv4 + IPv6 machines
      * [Apple ChatServer] Fixes crash possible when two s2s instances