Glue wildcard records processing.

ns_put_glues() now copies the glues one by one and if a wildcard
  is encountered, the RR is copied and owner is replaced by name
  found by searching through the NS RRs in Authority section.
  (This approach should be faster than using the zn_get_glue()
   method for each name and type as in that case we would need to
   always iterate through the Authority section and in each
   iteration iterate over the glue records.)

zn_get_glue() now processes wildcard glue records. (The function
  however is not used right now.)

Fix in zdb_process_nonauth() (should not free the list of names).
Changed zdb_dname_list_contains() to zdb_dname_list_find() which
  returns the found name. Not utilized now. (May change back later)