* nis/nis_domain_of.c (__nis_domain_of): New function.
* include/rpcsvc/nislib.h (__nis_domain_of): New prototype.
* nis/nis_lookup.c (nis_lookup): Use __nis_domain_of.
* nis/nis_call.c (rec_dirsearch): Likewise.
(first_shoot): Likewise. Remove search_parent_first argument.
(struct nis_server_cache): Rename search_parent_first field
to search_parent.
(nis_server_cache_search, nis_server_cache_add): Rename
search_parent_first argument to search_parent.
(__nisfind_server): Likewise. If search_parent, call
__nis_domain_of.