Also allows us to remove sysdb_subdom_get<pw/gr>nam() wrappers and restore
fqnames proper value in subdomains, by testing for a parent domain being
present or not.

Bring it out of sysdb, which will slowly remove internal dependencies on
domains and instead will always require them to be passed by callers.

https://fedorahosted.org/sssd/ticket/1612

This patch changes the handling of ghost attributes when saving the
actual user entry. Instead of always linking all groups that contained
the ghost attribute with the new user entry, the original member
attributes are now saved in the group object and the user entry is only
linked with its direct parents.

As the member attribute is compared against the originalDN of the user,
if either the originalDN or the originalMember attributes are missing,
the user object is linked with all the groups as a fallback.

The original member attributes are only saved if the LDAP schema
supports nesting.

https://fedorahosted.org/sssd/ticket/1589

Added check for determining, whether database version is higher or
lower than expected. To distinguish it from other errors it uses
following retun values (further used for appropriate error message):
EMEDIUMTYPE for lower version than expected
EUCLEAN for higher version than expected

When SSSD or one of it's tools fails on DB version mismatch, new error
message is showed suggesting how to proceed.

https://fedorahosted.org/sssd/ticket/1495

https://fedorahosted.org/sssd/ticket/1553

sss_seed fails if password file specified with -p or
--password-file option contains password longer than
PASS_MAX.

Man pages inform about PASS_MAX limitation.

When file is used to specify a password in sss_seed, then only
first line of this file is used.
Also empty passwords are treated as errors.

https://fedorahosted.org/sssd/ticket/1548