[SSSD] [PATCH] ad: support cross domain membership

[Pavel Březina]

https://fedorahosted.org/sssd/ticket/2064

These patch set depends on:
[PATCH] ad: store group in correct tree on initgroups via tokenGroups

You can also pull it with all dependencies from my repository:
fedorapeople.org:public_git/sssd.git #ad-groups

The fundamental changes in this patch set are:
- lookup groups in global catalog
- pick up member domain from its originalDN