1.10.0 (2022-03-20)

This is a feature release focused on compatibility, presentation and
ergonomics.

* New option: --animate <bool>. On by default. Can be turned off to replace
  animations with a still frame. Suggested by Lionel Dricot in github#79.

* New option: --center or -C <bool>. Off by default. Can be turned on to center
  images. Suggested by Lionel Dricot in github#83.

* New options: --margin-bottom <n> and --margin-right <n>. These permit
  using all available space (with --margin-bottom 0) or some smaller amount.
  Suggested by @crmabs in github#61.

* New option: --polite <bool>. On by default. Can be turned off to correct
  issues caused by previous terminal state (e.g. no sixel scrolling) and
  improve presentation (e.g. by temporarily hiding the cursor). This can
  leave the terminal in an altered state, which is somewhat rude.

* New option: --threads <n>. Allows manually specifying the number of threads
  to use. Defaults to one per detected logical CPU core.

* When invoked with redirected input and no arguments, act like a filter as
  if invoked with "-". Here's an example that downloads an image, converts it
  to Unicode text and mails it to hello@example.com:

  $ curl https://hpjansson.org/chafa/img/lc.jpg \
    | chafa -f symbols -c none -s 77 --invert --dither bayer \
    | mailx hello@example.com

* If input or output is being redirected, default to playing animations only
  once instead of looping forever. This can be overridden with '-d inf'.

* Replaced obsolete Autoconf macros (Mikel Olasagasti Uranga).

* Improved image loaders:
  - GIF: Load GIF87a images as well as GIF89a.
  - PNG: Add an internal copy of LodePNG, bypassing ImageMagick. This improves
    performance and helps with eventually phasing out the latter.
  - XWD: Support images generated by 'convert'.

* Improved terminal support:
  - Contour: Enable sixel support (Dmitry Atamanov).
  - foot: Open-ended TERM string matching (Daniel Eklöf).
  - Konsole: Enable sixel support (Dmitry Atamanov).
  - WezTerm: Enable sixel support.

* Bug fixes:
  github#76  Smolscale uses too much stack space (found by Hoang Nguyen).
  github#81  Chafa --version is returned to stderr, not stdout (found by
             Lionel Dricot).
  [unfiled]  Potential memory overrun when using Floyd-Steinberg dithering
             in symbols mode.
  [unfiled]  iTerm2 compatibility issue with WezTerm and possibly others.