OpenVPN Release 2.7_rc6

OpenVPN Release 2.7_rc6

version.m4, ChangeLog, Changes.rst

Changes.rst has not received an "2.7_rc6" section - it has the
"highlevel" overview of what is new in 2.7, but for alpha/beta/rc*
releases it's better to look at git log to see what has been added/fixed.

Notable changes rc5 -> rc6 are:
    - bugfix on restarting a p2mp server instance with SIGUSR1 (inadvertedly
      closing fd 0, causing a crash on the next restart - GH #966)
    - prevent NULL pointer crash on suitable combination of --dns-updown
      statements in openvpn config file (not pushable)
    - prevent inappropriate management interface activity if a password is
      set and --management-forget-disconnect or --management-signal are active
    - more conversion warnings fixed
    - Windows: interactive service - some initial unit tests added for the
      most complex string conversion function (ConvertItfDnsDomains())
    - remove #ifdefs around socket sendbuf/receive buf handling, assuming that
      all platforms that have POSIX sockets have this.
    - add mbedTLS 4 support
    - fix check for failed fork() in port-share code

Signed-off-by: Gert Doering <gert@greenie.muc.de>