rpn2cql_structure() supports proximity nodes (except that the Type-1 proximity node's "exclusion" binary is ignored, as there is no way to express that in CQL).  Fixes bug #4564.
rpn2cql_structure() supports proximity nodes (except that the Type-1
proximity node's "exclusion" binary is ignored, as there is no way to
express that in CQL).  Fixes bug #4564.

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