use the connector option for requiring the right connector manager

lib/sequelize.js

@@ -2,7 +2,6 @@ var Utils            = require("./utils")
   , ModelDefinition  = require("./model-definition")
   , DataTypes        = require('./data-types')
   , ModelManager     = require("./model-manager")
-  , ConnectorManager = require('./connector-manager')
 
 var Sequelize = module.exports = function(database, username, password, options) {
   options = options || {}
@@ -20,6 +19,8 @@ var Sequelize = module.exports = function(database, username, password, options)
     port    : options.port || 3306
   }
 
+  var ConnectorManager = require("./connectors/" + (options.connector || 'mysql') + "/connector-manager")
+
   this.modelManager = new ModelManager(this)
   this.connectorManager = new ConnectorManager(this.config)
 }