NODE-507 Added returnNonCachedInstance option to db.db

Author: christkv

lib/db.js

@@ -975,6 +975,7 @@ Db.prototype.addChild = function(db) {
  * @param {string} name The name of the database we want to use.
  * @param {object} [options=null] Optional settings.
  * @param {boolean} [options.noListener=false] Do not make the db an event listener to the original connection.
+ * @param {boolean} [options.returnNonCachedInstance=false] Control if you want to return a cached instance or have a new one created
  * @return {Db}
  */
 Db.prototype.db = function(dbName, options) {
@@ -985,7 +986,7 @@ Db.prototype.db = function(dbName, options) {
   }
 
   // Do we have the db in the cache already
-  if(this.s.dbCache[dbName]) {
+  if(this.s.dbCache[dbName] && options.returnNonCachedInstance !== true) {
     return this.s.dbCache[dbName];
   }