naOmitMulti: Remove NAs from one or more equal-length vectors
Description
This function removes elements in one or more equal-length vectors in which there is one NA at that position. For example, if there are three vectors A, B, and C, and A has an NA in the first position and C has an NA in the third position, then A, B, and C will each have the elements at positions 1 and 3 removed.