Add re-entrant CQL/Solr/RPN functions

The re-entrant functions are: cql_transform_r,
cql_transform_rpn2cql_stream_r, solr_transform_rpn2solr_stream_r.
These have same functionality as cql_transform,
cql_transform_rpn2cql_stream, solr_transform_rpn2solr_stream. They
return the additional infomration as WRBUF to make them re-entrant.