import samtools/bcftools/htslib 1.20

[ilia-kats]

No description provided.

[jmarshall]

Thanks for your PR, which is fairly comprehensively done. I wanted to fix the fclosing-stdout thing a different way (by not closing it in samtools/bamtk.c.pysam.c), and it has now been superseded by PR #1310, which imports 1.21.

(Incidentally pysam.sort("-n", …) has always sorted by name; SAMtools v1.19 merely introduced -N with a slightly different name-sorted sort order.)