[SSSD] Announcing SSSD 2.3.0

[Pavel Březina]

# SSSD 2.3.0

The SSSD team is proud to announce the release of version 2.3.0 of the
System Security Services Daemon. The tarball can be downloaded from:
     https://github.com/SSSD/sssd/releases/tag/sssd-2_3_0

See the full release notes at:
     https://sssd.github.io/docs/users/relnotes/notes_2_3_0

RPM packages will be made available for Fedora shortly.

## Feedback

Please provide comments, bugs and other feedback via the sssd-devel
or sssd-users mailing lists:
     https://lists.fedorahosted.org/mailman/listinfo/sssd-devel
     https://lists.fedorahosted.org/mailman/listinfo/sssd-users

## Highlights

### New features

- SSSD can now handle `hosts` and `networks` nsswitch databases (see 
`resolve_provider` option)
- By default, authentication request only refresh user's initgroups if 
it is expired or there is not active user's session (see 
`pam_initgroups_scheme` option)
- OpenSSL is used as default crypto provider, NSS is deprecated
- Active Directory provider now defaults to GSS-SPNEGO SASL mechanism 
(see `ldap_sasl_mech` option)
- Active Directory provider can now be configured to use only `ldaps` 
port (see `ad_use_ldaps` option)
- SSSD now accepts host entries from GPO's security filter
- Format of debug messages has changed to be shorter and better sortable
- New debug level (`0x10000`) was added for low level ldb messages only 
(see `sssd.conf` man page)

### Packaging changes

- New configure option `--enable-gss-spnego-for-zero-maxssf`

### Documentation Changes

- Default value of `ldap_sasl_mech` has changed to `GSS-SPNEGO` for AD 
provider
- Return code of `pam_sss.so` are documented in `pam_sss` manpage
- Added option `ad_update_samba_machine_account_password`
- Added option `ad_use_ldaps`
- Added option `ldap_iphost_object_class`
- Added option `ldap_iphost_name`
- Added option `ldap_iphost_number`
- Added option `ldap_ipnetwork_object_class`
- Added option `ldap_ipnetwork_name`
- Added option `ldap_ipnetwork_number`
- Added option `ldap_iphost_search_base`
- Added option `ldap_ipnetwork_search_base`
- Added option `ldap_connection_expire_offset`
- Added option `ldap_sasl_maxssf`
- Added option `pam_initgroups_scheme`
- Added option `entry_cache_resolver_timeout`
- Added option `entry_cache_computer_timeout`
- Added option `resolver_provider`
- Added option `proxy_resolver_lib_name`
- Minor text improvements