(a corn silage and manure supplier, as an unsecured creditor, brought an adversary complaint against a secured creditor seeking a declaratory judgment that the unsecured creditor’s claims were executory in nature which debtor must accept or reject, and to establish unsecured creditor’s right to an administrative claim and secured creditor moved to dismiss claim court determined that contracts were not executor because unsecured creditor had performed its part of the contracts, and only the payment by the debtor remained to be performed; unsecured creditor did not hold administrative claim because interval of time significantly greater than 20 days had passed between the unsecured creditor's performance and the debtor's petition date; unsecured creditor needed to bring adversary proceeding to avoid secured party’s interest in the property).