printing/cups: pack requested-attributes with IPP_TAG_KEYWORD

printing/cups: pack requested-attributes with IPP_TAG_KEYWORD

The CUPS IPP_GET_JOBS requested-attributes array indicates which job
attributes the caller would like in the cupsd response.

Until now, Samba has packed these attributes with a IPP_TAG_NAME
format tag. In recent versions of CUPS, this results in the IPP_GET_JOBS
response only including the job-id and job-printer-uri fields, even with
JobPrivateValues=none configured.

Bug: https://bugzilla.samba.org/show_bug.cgi?id=10808

Signed-off-by: David Disseldorp <ddiss@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Tue Feb 10 01:38:58 CET 2015 on sn-devel-104

(cherry picked from commit 2f4998113e539ea4ba6fb0a72ba6ac25c9d74bd6)

Autobuild-User(v4-0-test): Karolin Seeger <kseeger@samba.org>
Autobuild-Date(v4-0-test): Tue Feb 10 23:14:19 CET 2015 on sn-devel-104