Added new methods:

    $translation->cdna_start();    # or...
    $translation->cdna_start($transcript);
        # Returns the start position of the translation in cDNA
        # coordinates.  Providing the transcript explicitly speeds
        # things up a bit.  The transcript is used in a call to
        # $exon->cdna_coding_start($transcript);

    $translation->cdna_end();    # or...
    $translation->cdna_end($transcript);
        # Returns the end position of the translation in cDNA
        # coordinates.  Providing the transcript explicitly speeds
        # things up a bit.  The transcript is used in a call to
        # $exon->cdna_coding_end($transcript);


    $translation->genomic_start();
        # Returns the start position of the translation in genomic
        # coordinates on the forward strand.

    $translation->genomic_end();
        # Returns the end position of the translation in genomic
        # coordinates on the forward strand.