What's new:
-----------

- Drop support for Windows 7, Windows 8, Server 2008 R2 and Server 2012.

- The console device gets accessible from other terminals such as other
  consoles and ptys. Thanks to this new feature, GNU screen and tmux
  now work in the console.

- newgrp(1) tool.

- cygcheck has new options searching for available packages in the
  cygwin distro, as well as getting extended info on available and
  installed packages.

- fnmatch(3) and glob(3) now support named character classes, equivalence
  class expressions, and collating symbols in the search pattern, i.e.,
  [:alnum:], [=a=], [.aa.].

- Introduce /dev/disk directory with various by-* subdirectories which
  provide symlinks to disk and partition raw devices:
  by-drive/DRIVE_LETTER ->  ../../sdXN
  by-label/VOLUME_LABEL ->  ../../sdXN
  by-id/BUSTYPE-[VENDOR_]PRODUCT_[SERIAL|0xHASH][-partN] -> ../../sdX[N]
  by-partuuid/MBR_SERIAL-OFFSET -> ../../sdXN
  by-partuuid/GPT_GUID -> ../../sdXN
  by-uuid/VOLUME_SERIAL -> ../../sdXN
  by-voluuid/MBR_SERIAL-OFFSET -> ../../sdXN
  by-voluuid/VOLUME_GUID -> ../../sdXN
  The subdirectories by-drive and by-voluuid are Cygwin specific.

- Introduce /proc/codesets and /proc/locales with information on
  supported codesets and locales for all interested parties.  Locale(1)
  opens these files and uses the info for printing locale info like any
  other process could do.

- Add support for GB18030 codeset.

- Add support for lseek flags SEEK_DATA and SEEK_HOLE, a GNU extension.

- New API calls: posix_spawn_file_actions_addchdir_np,
  posix_spawn_file_actions_addfchdir_np.

- New API calls: c8rtomb, c16rtomb, c32rtomb, mbrtoc8, mbrtoc16, mbrtoc32.

- New API call: fallocate (Linux-specific).

- Implement OSS-based sound mixer device (/dev/mixer).

What changed:
-------------

- posix_spawnp no longer falls back to starting the shell for unrecognized
  files as execvp.  For the reasoning, see
  https://www.austingroupbugs.net/view.php?id=1674

- FIFOs now also work over NFS.

- Enable automatic sparsifying of files on SSDs, independent of the
  "sparse" mount mode.