update to htslib 1.10

[dlaehnemann]

htslib has recently had a big release with lots of bugfixes and new stuff, for example APIS for SAM headers and AWS S3:
https://github.com/samtools/htslib/releases/tag/1.10

This will very likely require a bunch of changes, so this is an issue to track any work on updating this wrapper to the new version.

[brainstorm]

Shall we close this issue in favour of #184? I would like to have efforts on this focused on the PR since it might confuse people wanting to help out and seeking comments in both places... I would be confused :-S

[dlaehnemann]

Yes, sure. This issue was merely meant to track any discussion before a PR exists or in case there would be mutliple PRs. But with your major efforts over at PR #184 progressing so fast and cited here, no reason to keep this issue open!