Changed yaz_record_conv_record to be reentrant.
Changed yaz_record_conv_record to be reentrant.

Changed yaz_record_conv_record and yaz_record_conv_opac_record to be
reentrant. Now yaz_iconv_t is created for each invocation.

dcrossleyau/yaz,dcrossleyau/yaz,nla/yaz,dcrossleyau/yaz,nla/yaz,nla/yaz,nla/yaz