devkit: use your own exports in grunt tasks

external/amber-dev/tasks/grunt-amberc.js

@@ -1,6 +1,6 @@
 module.exports = function (grunt) {
 
-    var amberc = require('../lib/amberc');
+    var amberc = require('..').amberc;
 
     /**
      A full example entry for a Gruntfile.js is available below.

external/amber-dev/tasks/grunt-amdconfig.js

@@ -27,7 +27,7 @@ module.exports = function (grunt) {
             grunt.fail.warn('Only one destination file supported.');
         }
 
-        require('../lib/config.js').writeConfig(options.root_dir, this.files[0].dest, function (err) {
+        require('..').configBuilder.writeConfig(options.root_dir, this.files[0].dest, function (err) {
             done(!err);
         })
     });