J (74) in qualities

[idot]

We also get a J (74, 41 in bam) after samtools view. It seems as if illumina2bam takes the illumina 1.8 phred value that goes up to 41.
I just checked and it seems to be legal from the bam spec.

There are some tools that quit. I think its important to point the resulting range out in the documentation. I think reducing J to I automatically is not so good.