Differentiate between subject references and nested nodes.

Author: dlongley

tests/compact/c015-in.jsonld

@@ -3,8 +3,14 @@
   "http://example/p": [{
     "@id": "http://example/typed-base#typed-id",
     "@type": ["http://example/Type"],
-    "http://example/nested": [{
-      "@id": "http://example/base-base#nested-id"
+    "http://example/subjectReference": [{
+      "@id": "http://example/typed-base#subject-reference-id"
+    }],
+    "http://example/nestedNode": [{
+      "@id": "http://example/base-base#nested-id",
+      "http://example/foo": [{
+        "@value": "bar"
+      }]
     }]
   }]
 }]

tests/compact/c015-out.jsonld

@@ -13,8 +13,12 @@
   "p": {
     "@id": "#typed-id",
     "@type": "Type",
-    "nested": {
-      "@id": "#nested-id"
+    "subjectReference": {
+      "@id": "#subject-reference-id"
+    },
+    "nestedNode": {
+      "@id": "#nested-id",
+      "foo": "bar"
     }
   }
 }