Support for the UserInformation DPU OCLC-UserInformation:

Support for the UserInformation DPU OCLC-UserInformation:
        - Add VAL_OCLCUI to oid.h
        - #include <yaz/z-oclcui.h> in include/yaz/proto.h
        - #define Z_External_OCLCUserInfo in include/yaz/prt-ext.h
        - Add Z_OCLC_UserInformation *oclc branch to Z_External.u
        - Add "OCLC-userInfo" entry to OID database in util/oid.c
        - New file "oclcui.asn" in z39.50 directory
        - Mention "oclcui.asn" and "z-oclcui.c" in z39.50/Makefile.am
        - Add VAL_OCLCUI registration in z39.50/prt-ext.c
        - Add arm to union-database in Z_External() in z39.50/prt-ext.c
        - Include UserInfoFormat-oclcUserInformation in z39.50/z.tcl
        (This is a handy checklist next time I need to add something.)
More verbose authentication-setting in command-line client.
Temporary debugging code in client (for OCLC diagnostics).