added extra methods to query builder to use in subqueries
added extra methods to query builder to use in subqueries

Luke265/typeorm,typeorm/typeorm,gintsgints/typeorm,ReaxDev/typeorm,cserron/typeorm,Luke265/typeorm,BradyLiles/ionic-orm,typeorm/typeorm,wpensar/ionic-orm,ReaxDev/typeorm,wpensar/ionic-orm,gintsgints/typeorm,BradyLiles/ionic-orm,cserron/typeorm,wpensar/ionic-orm,typeorm/typeorm