Make most of the Draft 05 changes to meta-schemas

Core and Validation:
* Add "$ref" to definitions (but don't integrate it yet as that
  requires some reorganization).
* Use the newly added "uriref" format where appropriate.

Hyper-Schema:
* "rel" is now optional
* Add "base"
* Remove "fragmentResolution" and "pathStart"

Author: handrews

draft-05/hyper-schema

@@ -10,7 +10,7 @@
         "linkDescription": {
             "title": "Link Description Object",
             "type": "object",
-            "required": [ "href", "rel" ],
+            "required": [ "href"],
             "properties": {
                 "href": {
                     "type": "string"
@@ -82,13 +82,13 @@
         "oneOf": { "$ref": "#/definitions/schemaArray" },
         "not": { "$ref": "#" },
 
+        "base": {
+            "type": "string"
+        },
         "links": {
             "type": "array",
             "items": { "$ref": "#/definitions/linkDescription" }
         },
-        "fragmentResolution": {
-            "type": "string"
-        },
         "media": {
             "type": "object",
             "properties": {
@@ -99,10 +99,6 @@
                     "type": "string"
                 }
             }
-        },
-        "pathStart": {
-            "type": "string",
-            "format": "uri"
         }
     }
 }

draft-05/links

@@ -3,7 +3,7 @@
     "id": "http://json-schema.org/draft-05/links",
     "title": "Link Description Object",
     "type": "object",
-    "required": [ "href", "rel" ],
+    "required": [ "href" ],
     "properties": {
         "href": {
             "type": "string"

draft-05/schema

@@ -3,6 +3,16 @@
     "id": "http://json-schema.org/draft-05/schema",
     "title": "Core schema meta-schema",
     "definitions": {
+        "jsonReference": {
+            "type": "object",
+            "properties": {
+                "$ref": {
+                    "type": "string",
+                    "format": "uriref"
+                }
+            },
+            "required": [ "$ref" ]
+        },
         "schemaArray": {
             "type": "array",
             "minItems": 1,
@@ -40,7 +50,7 @@
     "properties": {
         "id": {
             "type": "string",
-            "format": "uri"
+            "format": "uriref"
         },
         "$schema": {
             "type": "string",