Fix warnings in project.json

PR #2493 introduced the new project.json schema. The tree has 118 files
with the old schema, which added several hundred warnings.

This change can't go in until PR #2864 does - it relies on those bug
fixes.

tools/MultiProjectValidator/project.json

@@ -1,13 +1,17 @@
 {
   "version": "1.0.0-*",
   "name": "pjvalidate",
-  "compilationOptions": {
+  "buildOptions": {
     "emitEntryPoint": true
   },
   "dependencies": {
     "NETStandard.Library": "1.5.0-rc2-24027",
-    "Microsoft.DotNet.ProjectModel": { "target": "project" },
-    "Microsoft.DotNet.Cli.Utils": { "target": "project" }
+    "Microsoft.DotNet.ProjectModel": {
+      "target": "project"
+    },
+    "Microsoft.DotNet.Cli.Utils": {
+      "target": "project"
+    }
   },
   "frameworks": {
     "netstandardapp1.5": {
@@ -16,4 +20,4 @@
       ]
     }
   }
-}
+}