Allow collapse and expand of source code

src/Microsoft.AspNetCore.Diagnostics/DeveloperExceptionPage/Views/ErrorPage.js

@@ -137,7 +137,7 @@
     };
 
     function frame(el) {
-        ns(el).children(".source .collapsible").toggle();
+        ns(".source .collapsible", el).toggle();
     }
 
     function tab(el) {

src/PageGenerator/Program.cs

@@ -14,7 +14,7 @@ namespace PageGenerator
     {
         private const int NumArgs = 1;
 
-        public void Main(string[] args)
+        public static void Main(string[] args)
         {
             if (args.Length != NumArgs)
             {

src/PageGenerator/project.json

@@ -3,6 +3,7 @@
   "description": "Builds the pages for the Diagnostics projects. Runs in build.cmd.",
   "compilationOptions": {
     "warningsAsErrors": true,
+    "emitEntryPoint": true,
     "keyFile": "../../tools/Key.snk"
   },
   "repository": {