Improve display of MARC records with multi-byte subfield IDs YAZ-695
Improve display of MARC records with multi-byte subfield IDs YAZ-695

In some rare cases subfield identifiers are multi-byte characters.
This will try to deterime length of those and split accordingly.
This affects display in line mode as MARCXML/MarcXchange. The encoding
of ISO2709 is the same.

dcrossleyau/yaz,dcrossleyau/yaz,dcrossleyau/yaz