[SSSD] [PATCHES] Wildcard lookups for InfoPipe

Hi, the attached patches implement https://fedorahosted.org/sssd/ticket/2553. I'm sorry the patches took so long, but only during testing I realized the deleting of users not updated by the wildcard lookup is flawed. In case there were more entries in cache that match the wildcard than the limit on the wildcard search, we might be deleting legitimate entries that might contain cached credentials.. What I did instead was never remove any entries during wildcard lookups, but instead, only return entries that were updated during the wildcard lookup in the cache_req. That way, stale entries would be deleted by a direct lookup (maybe as a result of getpwuid when examining a file) or can be deleted by the cleanup task. I'm a bit nervous about the LDAP changes, please review ruthlessly :-) I would also like for the option defaults to be carefully checked during review. One question about the by-name-and-domain lookups -- should we check the domain we receive from the cache_req is the same as we requested? btw I really like how the cache_req and the infopipe code are structured. It was quite easy to extend without any hacks.