The assignee may dispose of and sell all the estate assigned, real and personal, which the debtor had at the time of the assignment, may sue for and recover in the assignee’s own name everything belonging or appertaining to said estate, and generally do whatever the debtor might have done in the premises; but no sale of real estate belonging to said trust shall be made without notice published as in case of sales of real estate on execution, unless the court or judge shall otherwise order, and no such sales shall be valid until approved by the court or judge.