Update to 2.8.1.0. From the changelog:

- Added skalibs_regcomp(), accepting empty regexes on BSDs.
- Bugfixes.
- Better reporting in utc_from_tai() and localtm_from_*()
- avltreeb removed. (It used VLAs inside of structures, which is
  GNU C, not C99.) The AVLTREEN_DECLARE_AND_INIT() macro should be
  used instead.
- New functions: env_dump(), mk?temp(), autosurf(), autosurf_name()
- mkdir_unique() removed. (Duplicate functionality with mkdtemp.)
- ancilautoclose and nbwaitall sysdeps removed.
- New header: skalibs/posixishard.h
- Static libraries are now PIC by default.

(schmonz)