Atomic install, remove locking, cache xz archives (for offline installs)

Reviewed By: martinbigio

Differential Revision: D3015398

fb-gh-sync-id: e0d987917b94ce541c8fa890930799aa8613737e
shipit-source-id: e0d987917b94ce541c8fa890930799aa8613737e

packager/blacklist.js

@@ -13,6 +13,7 @@ var path = require('path');
 // Don't forget to everything listed here to `package.json`
 // modulePathIgnorePatterns.
 var sharedBlacklist = [
+  /js\/tmp\/.*/,
   /node_modules[/\\]react[/\\]dist[/\\].*/,
   'node_modules/react/lib/React.js',
   'node_modules/react/lib/ReactDOM.js',