(a) Property covered by a general power of appointment which, when created, is not presently exercisable is subject to the payment of the claims of creditors of the donee, his estate and the expenses of administering his estate, only:
(1) If the power was created by the donee in favor of himself; or
(2) If a postponed power becomes exercisable in accordance with the terms of the creating instrument, except in the case of a testamentary general power.