cups-filters: Update to 1.26.1

Changes:
1.26.1
------
- build system: Install the "implicitclass" backend with
  "-rwx------" permissions, so that CUPS executes it as root,
  as the "ipp" CUPS backend also has to be executed as root
  (Issue #183).
- build system: Fixed setting permissions when installing the
  "cups-brf" backend.
- libcupsfilters: When using the
  "media-{bottom,left,right,top}-margin-supported" IPP
  attributes (needed if we have no "media-col-database"), use
  the minimum and not the maximum margins, this allows
  accessing more of the printer's capabilities, especially for
  legacy printers which do not provide sufficient information
  (Issue #22).

1.26.0
------
- cups-browsed: When generating local queues for printers for
  which the local CUPS daemon would provide temporary queues
  use the PPDs generated by libcupsfilters and not the ones
  generated by CUPS. The PPD generation of libcupsfilters also
  works with IPP-1.x-only printers, printers which do not
  support to query "media-col-database" and printers which
  support driverless printing only via PCLm. This can be
  changed via the "UseCUPSGeneratedPPDs" directive in
  cups-browsed.conf (Issue #22).
- libcupsfilters: Re-structured the get_printer_attributes()
  function to remove the recursive calls for the fallbacks, to
  check required attributes in the response only if requested,
  and to fully integrate the method of getting a suitable
  response for a full printer capability list also if the
  printer is only IPP 1.1 or does not support the
  "media-col-database" attribute (Issue #22, Issue #163).
- libcupsfilters, cups-browsed, driverless: Moved the funtions
  get_printer_attributes() and resolve_uri() from cups-browsed
  into libcupsfilters, to share them with the driverless
  utility (Issue #22).
- implicitclass: Fixed wrong stdout redirection from the
  filters to the IPP backend and hard-coded path for "ipp"
  backend call (Possible fix for Issue #163, Issue #181).
- cups-browsed, driverless: Use DNS-SD-service-name-based URIs
  instead of host-name-based ones, as CUPS also does. In
  cups-browsed one can switch back to the conventional
  host-name-based URIs via the new "DNSSDBasedDeviceURIs"
  configuration option.  Note that cups-browsed always uses
  conventional URIs for printers discovered via legacy CUPS
  browsing or LDAP.
- cups-browsed: When removing a CUPS queue, do not consider an
  error (and retry) if the queue does not actually exist. Also
  ignore errors when checking whether there are still
  jobs. This way when a new queue gets created and the
  generation of the PPD file fails the attempt to remove this
  non-existing queueu when removing the printer entry does not
  cause any problem.
- cups-browsed: Improved the fallback mechanism of the
  get_printer_attributes() function. Instead of considering
  the request failed by the content of the response only when
  not more than the two language atrributes come out, we check
  through a list of required attributes whether they are all
  there.  In addition, we actually fail when all callbacks
  have failed (Issue #22).
- cups-browsed: Introduced new configuration options
  "UpdateCUPSQueuesMaxPerCall" and
  "PauseBetweenCUPSQueueUpdates" to limit the amount of local
  CUPS queues created, modified, or removed in a single event
  callback. Before, when there were thousands of printers in
  the network, cups-browsed got blocked for other tasks, like
  assigning a destination printer for a cluster print job
  (Issue #163).

1.25.13
-------
- implicitclass: When passing on the job via the "ipp" CUPS
  backend, set argv[0] to the destination printer URI (Pull
  request #173).
- cups-browsed: Added another fallback to the
  get-printer-attributes IPP request: Now after failing the
  standard request ("all", "media-col-database") with both IPP
  2.0 and IPP 1.1, try simply "all", without
  "media-col-database" (Pull request #173).
- cups-browsed: Do not set printer-is-shared for remote CUPS
  queue when making a temporary queue permanent (Pull request
  #180).
- cups-browsed: Fix leaks of ipp_t struct and load balancing
  on the servers (Pull request #179).
- cups-browsed, implicitclass: Prioritize Apple Raster against
  PWG Raster when selecting the PDL for the destination
  printer for a job sent to a cluster, also cleaned up the PDL
  selector code and added PostScript support.
- libcupsfilters: Updated the PPD generator adding all changes
  of the PPD generator of CUPS: Support for "job-account-id",
  "job-accounting-user-id", "job-password", finishing options
  "trim-..." added, finishing options and
  "finishing-col-database" support synced with CUPS.
- libcupsfilters: In the PPD generator get the mode for
  handling the back sides of the sheets when printing duplex
  preferrably from the "urf-supported" attribute.
- libcupsfilters: Fixed bug that the PPD generator did not
  output the "*CloseUI: *ColorModel" line when it did not
  determine a default setting for "ColorModel".
- cups-browsed: Added some missing memory allocations leading
  to a segfault (Issue #175).

1.25.12
-------
- libcupsfilters: Use the text names "Draft", "Normal", and
  "High" instead of 3, 4, and 5 as choice names for the
  "cupsPrintQuality" option as CUPS does (Issue #171).
- libcupsfilters: If a printer supports both Apple Raster and
  PWG Raster let the generated PPD use Apple Raster as there
  are several printers which report PWG Raster support but do
  not actually print PWG Raster (Pull reguest #168, Issue
  #171, CUPS issue #5238).
- cups-browsed: Fix unset location check to use DNS-SD field
  (Pull request #172).
- libcupsfilters, beh, implicitclass, foomatic-rip,
  imagetopdf, mupdftoraster, pdftops, sys5ippprinter,
  cups-browsed, driverless: Silenced all compiler warnings to
  make the build process of cups-filters completely free of
  warnings.
- pdftops: Fixed crash when using filter without PPD file.
- pdftops: If printing grayscale jobs with Ghostscript as PDF
  renderer, add "-sProcessColorModel=DeviceGray" to
  Ghostscript command line.
- pdftops: Do not use the ugly "pdftops -level1 ..."
  workaround to get grayscale PostScript output from
  Poppler. It leads to huge output files with Poppler's
  "pdftops" utility and does not work at all with
  "pdftocairo".  Poppler itself does not support PostScript
  output converted to grayscale. Issue a warning with the hint
  to use Ghostscript or MuPDF as PDF renderer (Issue #169).
- libcupsfilters: In the cupsRasterParseIPPOptions()
  accept also "Mono", "Monochrome", and "Gray" as color
  space names.

(leot)