remove hard require to query generator (should go through dialect instead)

lib/query-interface.js

@@ -14,10 +14,7 @@ module.exports = (function() {
   **/
   **/
   var QueryInterface = function(sequelize) {
   var QueryInterface = function(sequelize) {
     this.sequelize = sequelize;
     this.sequelize = sequelize;
-    this.QueryGenerator = require('./dialects/' + this.sequelize.options.dialect + '/query-generator');
-    this.QueryGenerator.options = this.sequelize.options;
-    this.QueryGenerator._dialect = this.sequelize.dialect;
-    this.QueryGenerator.sequelize = this.sequelize;
+    this.QueryGenerator = this.sequelize.dialect.QueryGenerator;
   };
   };
 
 
   QueryInterface.prototype.createSchema = function(schema) {
   QueryInterface.prototype.createSchema = function(schema) {