[poppler] Poppler 21.01.0 released

[Albert Astals Cid]

Available from
http://poppler.freedesktop.org/poppler-21.01.0.tar.xz

The tarball is signed at http://poppler.freedesktop.org/poppler-21.01.0.tar.xz.sig with my key
http://hkps.pool.sks-keyservers.net/pks/lookup?op=get&search=0xCA262C6C83DE4D2FB28A332A3A6A4DB839EAA6D7

Note: There may be an issue on MSVC, the unofficial appveyor CI is crashing in one of the tests https://ci.appveyor.com/project/tsdgeos/poppler-mirror but i have not been able to reproduce it locally, more eyes welcome in this regard.

Release 21.01.0
core:
 * Faster routines for jpeg decoding
 * Fix reading signatures in encrypted files
 * Add white point correction when lcms is used
 * JBIG2Stream: Fix byte counting
 * Fix potential data loss if we try to fetch a non existing Ref after modifying the document
 * Specifically use DeviceGray instead of DefaultGray for softmasks
 * Fix various issues handling broken files

utils:
 * pdftocairo: Setmode binary for windows
 * pdfsig: Add hability to digitally sign files
 * pdftoppm: add options to set DeviceGray/DeviceRGB/DeviceCMYK
 * pdftops: add options to set DeviceGray/DeviceRGB/DeviceCMYK
 * pdfimages: Account for rotation in PPI calculation

qt5:
 * Add hability to digitally sign files

qt6:
 * Add hability to digitally sign files

build system:
 * Enable clang-tidy bugprone-signed-char-misuse

This release was brought to you by Adam Sampson, Albert Astals Cid, Hans-Ulrich Jüttner, Jakub Alba, Katarina Behrens, Lluís Batlle i Rossell, Nelson Benítez León, Oliver Sander, Philipp Knechtges, Salvo Miosi, Thomas Freitag, Thorsten Behrens, William Bader, mrbax and everyone else that filed bugs or helped with code reviews :)

Testing, patches and bug reports welcome.

Cheers,
  Albert