(estate included assets transferred to family limited partnership; no bona fide sale and decedent retained control over assets; decedent retained economic benefits and control over property and transfers did not involve bona fide sale for full consideration; FLP paid over $200,000 of decedent's estate taxes from FLP funds which indicated implicit agreement that transferor would retain enjoyment of transferred property; however, estate entitled to equitable recoupment for income taxes that children and grandchildren overpaid on sale of the assets).