move code generator to a module

lib/contracts/code_templates/main-context.js.ejs

@@ -1,3 +0,0 @@
-var __mainContext = __mainContext || (
-  this ? this : typeof self !== 'undefined' ? self : void 0
-);

lib/core/engine.js

@@ -173,6 +173,10 @@ class Engine {
       self.events.request("code-generator:embarkjs:build", () => {
         self.events.emit('code-generator-ready');
       });
+
+      //self.codeGenerator.buildEmbarkJS(function() {
+      //  self.events.emit('code-generator-ready');
+      //});
     };
     const cargo = async.cargo((_tasks, callback) => {
       generateCode();