Translates nucleotide strings (DNA or RNA) into amino acid sequences
using the standard genetic code. A vector of sequences (strings) can be used as
input, and a corresponding vector of amino acid strings are returned. Stop
codons are translated into *. Alien characters (not A, C, G, U or T) will be tolerated in the third codon position in those cases where the third character is irrelevant for the translation. In all other cases, a codon containing an alien will be translated into X.