Transition to netstandard.

- dotnet5.X => netstandard1.y (where y = x-1).
- DNXCore50 => netstandardapp1.5.
- Applied the same changes to ifdefs.

src/Microsoft.AspNetCore.Html.Abstractions/project.json

@@ -8,7 +8,9 @@
   "compilationOptions": {
     "warningsAsErrors": true,
     "keyFile": "../../tools/Key.snk",
-    "nowarn": [ "CS1591" ],
+    "nowarn": [
+      "CS1591"
+    ],
     "xmlDoc": true
   },
   "dependencies": {
@@ -21,11 +23,14 @@
         "System.Runtime": ""
       }
     },
-    "dotnet5.4": {
+    "netstandard1.3": {
       "dependencies": {
         "System.Collections": "4.0.11-*",
         "System.Resources.ResourceManager": "4.0.1-*"
-      }
+      },
+      "imports": [
+        "dotnet5.4"
+      ]
     }
   }
-}
+}

src/Microsoft.Extensions.WebEncoders/project.json

@@ -9,7 +9,9 @@
     "warningsAsErrors": true,
     "allowUnsafe": true,
     "keyFile": "../../tools/Key.snk",
-    "nowarn": [ "CS1591" ],
+    "nowarn": [
+      "CS1591"
+    ],
     "xmlDoc": true
   },
   "dependencies": {
@@ -24,6 +26,10 @@
         "System.Runtime": ""
       }
     },
-    "dotnet5.4": {}
+    "netstandard1.3": {
+      "imports": [
+        "dotnet5.4"
+      ]
+    }
   }
-}
+}

test/Microsoft.AspNetCore.Html.Abstractions.Test/project.json

@@ -12,11 +12,14 @@
   },
   "testRunner": "xunit",
   "frameworks": {
-    "dnxcore50": {
+    "netstandardapp1.5": {
       "dependencies": {
         "dotnet-test-xunit": "1.0.0-dev-*"
       },
-      "imports": "portable-net451+win8"
+      "imports": [
+        "dnxcore50",
+        "portable-net451+win8"
+      ]
     },
     "net451": {
       "dependencies": {

test/Microsoft.Extensions.WebEncoders.Tests/project.json

@@ -12,11 +12,14 @@
     "keyFile": "../../tools/Key.snk"
   },
   "frameworks": {
-    "dnxcore50": {
+    "netstandardapp1.5": {
       "dependencies": {
         "dotnet-test-xunit": "1.0.0-dev-*"
       },
-      "imports": "portable-net451+win8"
+      "imports": [
+        "dnxcore50",
+        "portable-net451+win8"
+      ]
     },
     "net451": {
       "dependencies": {