(8) “Liability” includes any compensation for work or labour done, any obligation or possibility of an obligation to pay money or money's worth on the breach of any express or implied covenant, contract, agreement, or undertaking, whether such breach does or does not occur, or is or is not likely to occur or capable of occurring before the discharge of the debtor, and generally it shall include any express or implied engagement, agreement, or undertaking, to pay, or capable of resulting in the payment of money, or money's worth, whether the payment is, as respects amount, fixed or unliquidated; as respects time, present or future, certain or dependent on any one contingency or on 2 or more contingencies; as to mode of valuation, capable of being ascertained by fixed rules, or assessable only by fixed rules or as a matter of opinion.