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.

TestAssets/TestProjects/TestAppWithContentPackage/project.json

@@ -1,6 +1,6 @@
 {
   "version": "1.0.0-*",
-  "compilationOptions": {
+  "buildOptions": {
     "emitEntryPoint": true,
     "outputName": "AppWithContentPackage"
   },
@@ -9,6 +9,11 @@
     "SharedContentA": "1.0.0-*"
   },
   "frameworks": {
-    "netcoreapp1.0": { "imports": ["netstandardapp1.5", "dnxcore50"] }
+    "netcoreapp1.0": {
+      "imports": [
+        "netstandardapp1.5",
+        "dnxcore50"
+      ]
+    }
   }
-}
+}