Project Json mapping migration support

TestAssets/TestProjects/TestAppWithContents/Program.cs

@@ -7,7 +7,7 @@ namespace ConsoleApplication
         public static int Main(string[] args)
         {
             Console.WriteLine("Hello World!");
-            return 100;
+            return 0;
         }
     }
 }

TestAssets/TestProjects/TestAppWithContents/project.json

@@ -3,29 +3,30 @@
   "buildOptions": {
     "emitEntryPoint": true,
     "copyToOutput": {
-      "include": "testcontentfile.txt"
+      "include": "testcontentfile.txt",
+      "mappings": {
+        "dir/mappingfile.txt":{
+          "include": "testcontentfile2.txt"
+        },
+        "out/": {
+          "include": ["project.json", "Program.cs"],
+          "exclude": ["Program.cs"],
+          "includeFiles": ["Program.cs"],
+          "excludeFiles": ["Program.cs"]
+        }
+      }
     }
   },
   "dependencies": {
-    "Microsoft.NETCore.App": "1.0.1"
+    "Microsoft.NETCore.App": {
+      "version": "1.0.1",
+      "type": "platform"
+    }
   },
   "frameworks": {
     "netcoreapp1.0": {}
   },
   "publishOptions": {
     "include": "testcontentfile.txt"
-  },
-  "runtimes": {
-    "win7-x64": {},
-    "win7-x86": {},
-    "osx.10.10-x64": {},
-    "osx.10.11-x64": {},
-    "ubuntu.14.04-x64": {},
-    "ubuntu.16.04-x64": {},
-    "centos.7-x64": {},
-    "rhel.7.2-x64": {},
-    "debian.8-x64": {},
-    "fedora.23-x64": {},
-    "opensuse.13.2-x64": {}
   }
 }