Falcons API

1. List the documents that describe an entity

   The results are serialized in RDF/XML. Currently, at most 100 results will be served.

   Service URI: "http://iws.seu.edu.cn/services/falcons/api/whereis?" + entityURI
   The entityURI part should be encoded.

   For example, list the documents that describe the entity "http://xmlns.com/foaf/0.1/Person":
   http://iws.seu.edu.cn/services/falcons/api/whereis?http%3A%2F%2Fxmlns.com%2Ffoaf%2F0.1%2FPerson.