This is safe from ldb point of view, because ldb gurantees the data is
NULL-terminated. We must be careful before we save the data, though.

Resolves:
https://fedorahosted.org/sssd/ticket/2742

Reviewed-by: Pavel Březina <pbrezina@redhat.com>

Option dyndns_iface has now special value '*' which implies that IPs
from add interfaces should be sent during DDNS update.

Resolves:
https://fedorahosted.org/sssd/ticket/2549

Enable authenticating users from cache even when SSSD is in online mode.

Introduce new option `cached_auth_timeout`.

Resolves:
https://fedorahosted.org/sssd/ticket/1807

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>

Related to https://fedorahosted.org/sssd/ticket/2596

Reviewed-by: Pavel Březina <pbrezina@redhat.com>

Allows the administrator to extend the functionality of
ldap_purge_cache_timeout, ldap_user_principal and ldap_use_tokengroups to
the subdomains.

This is a less intrusive way of achieving:
    https://fedorahosted.org/sssd/ticket/2627

Reviewed-by: Pavel Reichl <preichl@redhat.com>

Resolves:
    https://fedorahosted.org/sssd/ticket/2644

Allows the administrators to extend ignore_group_members to subdomains
as well by setting:
    subdomain_inherit = ignore_group_members
in the domain section.

Reviewed-by: Pavel Reichl <preichl@redhat.com>

Adds a new option subdomain_inherit that would allow administrators to pick
and choose which option to pass to subdomains.

This option is required for:
    https://fedorahosted.org/sssd/ticket/2644
as a short-term fix.

The proper solution is described in:
    https://fedorahosted.org/sssd/ticket/2599

Reviewed-by: Pavel Reichl <preichl@redhat.com>