io_lib-1-14-15

This is a bug fix release.

Updates:

• Switched to using GitHub actions for CI.

• Updated htscodecs submodule to the latest version (1.3.0).
  Also fixed function names used within it.

• Minor code tidyups to remove compiler warnings.

Bug fixes:

• MacOS testing fix to cope with sed failing on long lines.

• Fixed bam_aux_skip B array handling of signed values.

• Improved detection of unsorted mode, which was causing a drastic
  slow-down when encoding unsorted data.

• Fixed a CRAM reference multi-threading bug when fetching from a
  fasta file.

• Fixed bam_aux_f decoding of floats.