URL-parsing+rendering part of the first two new convops ready

### Description
This PR implements the parsing of URL plus the rendering in XML and JSON of the first (/v1/contextTypes) of the batch of new convenience operations. A second new conv op is prepared for but not terminated (/v1/contextTypes/{entityType})

What is missing is the mongo part (see '#if 0' in serviceRoutines).

If you indent the variables it is much easier to read:

    BSONObj                   resultItem  = resultsArray[ix].embeddedObject();
    TypeEntity*               type        = new TypeEntity(resultItem.getStringField("_id"));
    std::vector<BSONElement>  attrsArray  = resultItem.getField("attrs").Array();