Update twosort.pkg

twosort.pkg

 d 'Group2': a general-purpose programming package for group quickly
 d 'CalculationVW': to calculate weighted variable by specificated weight
+d 'DivideVar': to divide the variable in varlist
 d
 d Distribution-Date: 20181206
 d
 F Group2.ado
 F CalculationVW.ado
+F DivideVar.ado