Use node's Environment feature to add "require" in renderer.

renderer/lib/init.coffee

@@ -0,0 +1,23 @@
+path = require 'path'
+
+# Expose information of current process.
+process.__atom_type = 'renderer'
+process.resourcesPath = path.resolve process.argv[1], '..', '..', '..'
+
+# We modified the original process.argv to let node.js load the
+# atom-renderer.js, we need to restore it here.
+process.argv.splice 1, 1
+
+# Add renderer/api/lib to require's search paths, which contains javascript part
+# of Atom's built-in libraries.
+globalPaths = require('module').globalPaths
+globalPaths.push path.join process.resourcesPath, 'renderer', 'api', 'lib'
+
+# And also common/api/lib
+globalPaths.push path.join process.resourcesPath, 'common', 'api', 'lib'
+
+# Expose global variables.
+global.require = require
+global.module = module
+global.__filename = __filename
+global.__dirname = __dirname