Changes 4.80:
 1. New authenticator driver, "gsasl".  Server-only (at present).
    This is a SASL interface, licensed under GPL, which can be found at
    http://www.gnu.org/software/gsasl/.
    This system does not provide sources of data for authentication, so
    careful use needs to be made of the conditions in Exim.
 2. New authenticator driver, "heimdal_gssapi".  Server-only.
    A replacement for using cyrus_sasl with Heimdal, now that $KRB5_KTNAME
    is no longer honoured for setuid programs by Heimdal.  Use the
    "server_keytab" option to point to the keytab.
 3. The "pkg-config" system can now be used when building Exim to reference
    cflags and library information for lookups and authenticators, rather
    than having to update "CFLAGS", "AUTH_LIBS", "LOOKUP_INCLUDE" and
    "LOOKUP_LIBS" directly.  Similarly for handling the TLS library support
    without adjusting "TLS_INCLUDE" and "TLS_LIBS".
    In addition, setting PCRE_CONFIG=yes will query the pcre-config tool to
    find the headers and libraries for PCRE.
 4. New expansion variable $tls_bits.
 5. New lookup type, "dbmjz".  Key is an Exim list, the elements of which will
    be joined together with ASCII NUL characters to construct the key to pass
    into the DBM library.  Can be used with gsasl to access sasldb2 files as
    used by Cyrus SASL.
 6. OpenSSL now supports TLS1.1 and TLS1.2 with OpenSSL 1.0.1.
    Avoid release 1.0.1a if you can.  Note that the default value of
    "openssl_options" is no longer "+dont_insert_empty_fragments", as that
    increased susceptibility to attack.  This may still have interoperability
    implications for very old clients (see version 4.31 change 37) but
    administrators can choose to make the trade-off themselves and restore
    compatibility at the cost of session security.
 7. Use of the new expansion variable $tls_sni in the main configuration option
    tls_certificate will cause Exim to re-expand the option, if the client
    sends the TLS Server Name Indication extension, to permit choosing a
    different certificate; tls_privatekey will also be re-expanded.  You must
    still set these options to expand to valid files when $tls_sni is not set.
    The SMTP Transport has gained the option tls_sni, which will set a hostname
    for outbound TLS sessions, and set $tls_sni too.
    A new log_selector, +tls_sni, has been added, to log received SNI values
    for Exim as a server.
 8. The existing "accept_8bitmime" option now defaults to true.  This means
    that Exim is deliberately not strictly RFC compliant.  We're following
    Dan Bernstein's advice in http://cr.yp.to/smtp/8bitmime.html by default.
    Those who disagree, or know that they are talking to mail servers that,
    even today, are not 8-bit clean, need to turn off this option.
 9. Exim can now be started with -bw (with an optional timeout, given as
    -bw<timespec>).  With this, stdin at startup is a socket that is
    already listening for connections.  This has a more modern name of
    "socket activation", but forcing the activated socket to fd 0.  We're
    interested in adding more support for modern variants.
10. ${eval } now uses 64-bit values on supporting platforms.  A new "G" suffix
    for numbers indicates multiplication by 1024^3.
11. The GnuTLS support has been revamped; the three options gnutls_require_kx,
    gnutls_require_mac & gnutls_require_protocols are no longer supported.
    tls_require_ciphers is now parsed by gnutls_priority_init(3) as a priority
    string, documentation for which is at:
    http://www.gnu.org/software/gnutls/manual/html_node/Priority-Strings.html
    SNI support has been added to Exim's GnuTLS integration too.
    For sufficiently recent GnuTLS libraries, ${randint:..} will now use
    gnutls_rnd(), asking for GNUTLS_RND_NONCE level randomness.
12. With OpenSSL, if built with EXPERIMENTAL_OCSP, a new option tls_ocsp_file
    is now available.  If the contents of the file are valid, then Exim will
    send that back in response to a TLS status request; this is OCSP Stapling.
    Exim will not maintain the contents of the file in any way: administrators
    are responsible for ensuring that it is up-to-date.
13. ${lookup dnsdb{ }} supports now SPF record types. They are handled
    identically to TXT record lookups.
14. New expansion variable $tod_epoch_l for higher-precision time.
15. New global option tls_dh_max_bits, defaulting to current value of NSS
    hard-coded limit of DH ephemeral bits, to fix interop problems caused by
    GnuTLS 2.12 library recommending a bit count higher than NSS supports.
16. tls_dhparam now used by both OpenSSL and GnuTLS, can be path or identifier.
    Option can now be a path or an identifier for a standard prime.
    If unset, we use the DH prime from section 2.2 of RFC 5114, "ike23".
    Set to "historic" to get the old GnuTLS behaviour of auto-generated DH
    primes.
17. SSLv2 now disabled by default in OpenSSL.  (Never supported by GnuTLS).
    Use "openssl_options -no_sslv2" to re-enable support, if your OpenSSL
    install was not built with OPENSSL_NO_SSL2 ("no-ssl2").
Fix build on SunOS and GCC>=4.6.
pixman hack is only required for X11_TYPE=native.
Fix build on SunOS and GCC>=4.6
Make Ejabberd user, group and directories configurable
Init scripts are only built on NetBSD.
Stop a silent dependency on LDAP if such is found.