Add exports folder to NODE_PATH

This is where all public classes will be exported through

exports/atom-api.coffee

@@ -0,0 +1,3 @@
+module.exports =
+  WorkspaceView: require './src/root-view'
+  fs: require './src/fs-utils'

src/atom-window.coffee

@@ -45,6 +45,7 @@ class AtomWindow
 
   setupNodePath: (resourcePath) ->
     paths = [
+      'exports'
       'src'
       'vendor'
       'static'