Further RNPM integration

Summary:
This commit removes `rnpm` folder that we left during initial merge to keep the diff cleaner. The `core`, `link` and `install` have now the same directory structure as any other command to make development more natural for all of us.

From most notable differences:
1) the `src` folder is now gone. The new structure should make it easier for people to work with the stuff and also move us closer to 100% rnpm integration,
2) There's also no `package.json` present in any of the `rnpm` packages, since they are no longer standalone modules,
3) There's no `bugs.url` in link.js since main package.json of React doesn't specify it. Decided to hardcode it to facebook/react-native since it's really unlikely to change. If one would prefer to use pkg.bugs.url as before, a separate PR modifying package.json should be sent.
Closes https://github.com/facebook/react-native/pull/9509

Differential Revision: D3751115

fbshipit-source-id: 74ae8330f7634df0887ad676808f47eee4b8de85

local-cli/core/findPlugins.js

@@ -0,0 +1,67 @@
+const path = require('path');
+const union = require('lodash').union;
+const uniq = require('lodash').uniq;
+const flatten = require('lodash').flatten;
+
+/**
+ * Filter dependencies by name pattern
+ * @param  {String} dependency Name of the dependency
+ * @return {Boolean}           If dependency is a rnpm plugin
+ */
+const isRNPMPlugin = (dependency) => dependency.indexOf('rnpm-plugin-') === 0;
+const isReactNativePlugin = (dependency) => dependency.indexOf('react-native-') === 0;
+
+const readPackage = (folder) => {
+  try {
+    return require(path.join(folder, 'package.json'));
+  } catch (e) {
+    return null;
+  }
+};
+
+const findPluginsInReactNativePackage = (pjson) => {
+  if (!pjson.rnpm || !pjson.rnpm.plugin) {
+    return [];
+  }
+
+  return path.join(pjson.name, pjson.rnpm.plugin);
+};
+
+const findPluginInFolder = (folder) => {
+  const pjson = readPackage(folder);
+
+  if (!pjson) {
+    return [];
+  }
+
+  const deps = union(
+    Object.keys(pjson.dependencies || {}),
+    Object.keys(pjson.devDependencies || {})
+  );
+
+  return deps.reduce(
+    (acc, pkg) => {
+      if (isRNPMPlugin(pkg)) {
+        return acc.concat(pkg);
+      }
+      if (isReactNativePlugin(pkg)) {
+        const pkgJson = readPackage(path.join(folder, 'node_modules', pkg));
+        if (!pkgJson) {
+          return acc;
+        }
+        return acc.concat(findPluginsInReactNativePackage(pkgJson));
+      }
+      return acc;
+    },
+    []
+  );
+};
+
+/**
+ * Find plugins in package.json of the given folder
+ * @param {String} folder Path to the folder to get the package.json from
+ * @type  {Array}         Array of plugins or an empty array if no package.json found
+ */
+module.exports = function findPlugins(folders) {
+  return uniq(flatten(folders.map(findPluginInFolder)));
+};