Update to 2.041

Upstream changes:
2.041    2021-07-27

    - Bug reports should now be made at GitHub Issues rather than RT.

    - Rename openpage to open_page in PDF::API2.  The old name is deprecated.

    - [RT #136648] Fix when writing PDFs containing cross-reference streams
      (reported by Chris Papademetrious, fix by Vadim Repin from RT #117184).

    - [RT #44877] GIFs containing comments or plain-text representations will no
      longer result in an error (reported by Chris Czub).

    - [RT #132844] Fix corruption when a PGM image is included (reported by Jeff
      Ratcliffe, fix by Vadim Repin).

    - Expand PNM support to include all image types.

    - [RT #131657] Disable recursion warnings while releasing (destroying) PDF
      indirect objects, which can be highly-interconnected (reported by Leon
      Winter).

    - [RT #41971] Fix when attempting to read an existing PDF's outlines
      (reported by Damyan Ivanov, fix based on a patch by Vadim Repin).

2.040    2021-04-13

    - Fix open() followed by stringify() resulting in a corrupt (mostly-empty)
      PDF, which was broken by changes in 2.039 (reported by Gareth Tunley).

    - [RT #134993] Calling open($filename) followed by saveas($same_filename)
      instead of update() resulted in a corrupt PDF in 2.039, which no longer
      reads the entire file into memory on open (reported by Marco Pessotto).

    - [RT #134957] Fix encoding of \n in a PDF string containing non-printable
      characters (reported by Stuart Henderson).

    - [RT #133131] Fix endianness of 64-bit numbers in cross-reference stream
      widths array (reported by Christopher Papademetrious, fix by Vadim Repin).

(wen)