Use systemd-lgin in preference to check if the user is logged in or not.
Fall back to the old method if no systemd-login support is available at compile
time or if it returns a fatal error, and can't determine the status of the user
on its own.
This will allow to consider a user really active (in order to reuse or refresh
crdentials) only if it really is logged into the system, and not just if one
of the user's processes is stuck around.

Resolves:
https://fedorahosted.org/sssd/ticket/2084

It was discovered that duplicating files in two subpackages is not
permitted by Fedora packaging guidelines[1]. This patch moves the PAC
responder to a new sssd-common-pac subpackage that both the sssd-ipa
and sssd-ad subpackages will require.

[1] https://fedoraproject.org/wiki/Packaging:Guidelines?rd=Packaging/Guidelines#DuplicateFiles

Now that we use the libkrb5 defaults for the default ccname template
we do not need the patch that changes the man pages defaults nor the
configure options to change sssd defaults anymore.

Related:
https://fedorahosted.org/sssd/ticket/2036

There was an inconsistency with how the warnings were specified and
how they were consumed by the macros. The result was that warnings were
hidden.

The NSS responder recently started using libsss_idmap in the getbysid
functions. The bug itself was spotted by one of our automated QA tools.

This will ensure that we aren't pulling in extra samba4
dependencies for the Kerberos provider.

The PAC responder is now used by both IPA and AD providers.

There are no longer any Fedora platforms running SSSD with SYSV
init scripts. We don't need the upgrade logic any more.

* Include localized pam_sss manpages in sssd-client
* Call ldconfig after libsss_nss_idmap is installed or removed