chore: move core modules into core directory

BREAKING CHANGE:
    This change moves the http module into angular2/, so its import
    path is now angular2/http instead of http/http.

    Many other modules have also been moved around inside of angular2,
    but the public API paths have not changed as of this commit.

modules/angular2/src/http/package.json

@@ -0,0 +1,17 @@
+{
+  "name": "ngHttp",
+  "version": "<%= packageJson.version %>",
+  "description": "Http module for Angular 2",
+  "homepage": "<%= packageJson.homepage %>",
+  "bugs": "<%= packageJson.bugs %>",
+  "contributors": <%= JSON.stringify(packageJson.contributors) %>,
+  "license": "<%= packageJson.license %>",
+  "repository": <%= JSON.stringify(packageJson.repository) %>,
+  "dependencies": {
+    "angular2": "<%= packageJson.version %>",
+    "rx": "<%= packageJson.dependencies['rx'] %>",
+    "reflect-metadata": "<%= packageJson.dependencies['reflect-metadata'] %>",
+    "traceur": "<%= packageJson.dependencies['traceur'] %>"
+  },
+  "devDependencies": <%= JSON.stringify(packageJson.defaultDevDependencies) %>
+}