some factory changes

lib/sequelize/Factory.js

 module.exports.Factory = function(Sequelize, sequelize) {
-  return {
+  var Factory = {
+    addManyToManyMethods: function(table1, table2, assocName, backAssocName) {
+      table1.prototype[Sequelize.Helper.SQL.addPrefix('get', assocName)] = Factory.createManyToManyGetter(table1, table2, assocName, backAssocName)
+      table1.prototype[Sequelize.Helper.SQL.addPrefix('set', assocName)] = Factory.createManyToManySetter(table1, table2, assocName, backAssocName)
+    },
+    
+    addOneToManyMethods: function(table1, table2, assocName, methodName) {
+      var setterName = Sequelize.Helper.SQL.addPrefix('set', methodName || assocName),
+          getterName = Sequelize.Helper.SQL.addPrefix('get', methodName || assocName)
+          
+      table1.prototype[setterName] = Factory.createOneToManySetter(table1, assocName)
+      table1.prototype[getterName] = Factory.createOneToManyGetter(table1, table2, assocName)
+      return table1
+    },
+    
     createManyToManyGetter: function(table1, table2, assocName, backAssocName) {
       return function(callback) {
         var Association = sequelize.tables[Sequelize.Helper.SQL.manyToManyTableName(assocName, backAssocName)].klass,
@@ -73,7 +87,7 @@ module.exports.Factory = function(Sequelize, sequelize) {
         })
       }
     },
-    createOneToManyGetter: function(table1, table2, assocName) {
+    createOneToManyGetter: function(table1, table2, assocName) {
       return function(callback) {
         var whereConditions = [Sequelize.Helper.SQL.asTableIdentifier(assocName), this.id].join("=")
         table2.findAll({where: whereConditions}, callback)
@@ -109,4 +123,6 @@ module.exports.Factory = function(Sequelize, sequelize) {
       }
     }
   }
+  
+  return Factory
 }
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