Bug in JSON-LD serialization

[lanthaler]

There's a bug in the JSON-LD serialization. Type coercions are applied to the full IRIs instead of applying them to the compact IRIs used in the document. Example:

{
  "@context": {
    "owl": "http://www.w3.org/2002/07/owl#",
    "rdfs": "http://www.w3.org/2000/01/rdf-schema#",
    "rdf": "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
    "http://www.w3.org/2000/01/rdf-schema#isDefinedBy": {  <-- should be rdfs:isDefinedBy
      "@type": "@id"
    },
    "http://www.w3.org/2000/01/rdf-schema#seeAlso": {      <-- should be rdfs:seeAlso
      "@type": "@id"
    }
  },
  "@id": "http://www.w3.org/ns/json-ld#context",
  "@type": "rdf:Property",
  "rdfs:label": {
    "@value": "JSON-LD context",
    "@language": "en"
  },
  "rdfs:isDefinedBy": {
    "@id": "http://www.w3.org/ns/json-ld",
    "@type": "owl:Ontology",
    "rdfs:label": {
      "@value": "The JSON-LD Vocabulary",
      "@language": "en"
    },
    "rdfs:comment": {
      "@value": "This is a vocabulary document and is used to achieve certain features of the JSON-LD language.",
      "@language": "en"
    }
  },
  "rdfs:seeAlso": "http://www.w3.org/TR/json-ld-syntax/#referencing-contexts-from-json-documents",
  "rdfs:comment": {
    "@value": "This link relation is used to reference a JSON-LD context from a JSON document so that it can be interpreted as JSON-LD.",
    "@language": "en"
  }
}