FASTR Format:
    The FASTR Format is identical to the FASTA Format except the
bases are replaced by numbers representing the read depth of the
corresponding bases in the given FASTA file. Since read depth
numbers may contain more than one digit (e.g. a read depth of
10) so each number is separated by a hyphen. Additionally, the
">" at the beginning of each entry is replaced by a "+".
    The FASTR file also features file size reducing features.
First, this script does not include entries with read-depths
of only zeroes (no alignments anywhere in entry) though there
is nothing against doing this in general. Also, the FASTR file
can list read depth as:
    16-16-16 or 3x16
The later is compressed and thus reduces total file size.

3-3-3-3-3-5-5-9-9-9-9-9-9

    is compressed to:

    5x3-2x5-6x9

FASTR Entry Example:

    +Corresponding FASTA or FASTQ header
    1-3x2-15x6-10-12x15

    or

    +Corresponding FASTA or FASTQ header
    1-2-2-2-6-6-6-6-6-6-6-6-6-6-6-6-6-6-6-10-15-15-15-15-15-15-15-15
    -15-15-15-15