fgallery 1.9

* A new flag `-k` allows to include the original files as-is, disabling
  all (lossless) transformations. Thanks to Rainer Müller.
* Handle gray-scale source images without failing during conversion.
* Handle UTF8 characters and whitespace in command-line arguments.
* Handle abnormal ``pngcrush`` failures with bad sRGB profiles.
* Improve default locale handling for text captions.
* Speed-up the gallery generation by avoiding copies when possible.
* Fix an error potentially occurring when the source gallery includes
  extra (non-image) files. Thanks to Alex Schroeder.
* Fix a typo in the man page thanks to Robin Paulson.
* Do not fail when producing the zip archive on galleries that have a
  lot of images or long file names.
* Update ``fcaption`` to Python3 and support both PyQt6 or PyQt5.
  Thanks to Chris Drexler for the Qt5 support.
* ``fcaption`` now sorts the input images by the file name, matching the
  default ``fgallery`` order. Thanks to Tom Conlin.
* Support ``7zz`` (from the new `7zip` package) in addition to ``7za``
  for archive generation.
* A new simple Makefile is provided to install ``fgallery`` and data
  files into an appropriate prefix.