(estate entitled to $11.7 million charitable deduction for amount paid to charitable trust in settlement of dispute with decedent's son concerning residuary estate; court concluded that decedent wanted residuary estate to pass to charitable trust, but failed to do so do solely to scrivener's error (all other testamentary instruments had provided for a charitable residuary bequest, but 1999 will failed to include it due to scrivener's error); I.R.C. Sec. 2056 has been narrowly construed to curtail marital deduction abuses, but I.R.C Sec. 2055 is designed to encourage charitable gifts; bona fide dispute existed as to whether charity had legal right to residuary estate; case distinguishable from Bach v. McGinnes, 333 F.2d 979 (3d Cir. 1964) on basis that no bona fide dispute concerning charity's legal entitlement to bequest existed in Bach).