zzuf 0.16.0
===========

Maintenance modernization of the 0.15 line for current Debian/Ubuntu/Kali
toolchains and packaging.

Build and portability
---------------------
* Declare missing glibc stream prototypes (`_IO_getc`, `__fseeko64`) and
  fortify `_*_chk` helpers used by `zzat`.
* Undefine `_FILE_OFFSET_BITS` / `_TIME_BITS` in libzzuf open/mmap/stream
  units so both 32-bit and 64-bit entry points stay distinct (Debian
  t64 / #1068663).
* Stop probing obsolete glibc `__open64` / `__fopen64` style aliases.
* Require autoconf 2.69+, use `AC_CONFIG_HEADERS` and bracketed `AC_INIT`.
* Enable `-Wall -Wextra` when the compiler accepts them.
* Include `libgen.h` for `basename` under modern glibc.
* Pull `errno.h` / `stdbool.h` into `zzat` for stricter C compilers.

Tests and CI
------------
* Drop `check-win32` from the default unix Automake test list.
* Detect statically linked or rust/uutils coreutils (`cat`/`dd`/`head`)
  and skip cases that cannot intercept those binaries (issue #31 class).
* Replace Travis CI with GitHub Actions (gcc + clang, `make check`).
* Make `check-source` fail fast with `set -e`.

Docs
----
* Refresh README for the 0.16 maintenance line.
* Point manpage URLs at the GitHub upstream.
* Manpage typo pass already present from upstream PR #29.
