[gimp/meson] (135 commits) ...Backport LibMyPaint modifications to meson.

[Félix Piédallu <fpiedallu src gnome org>]

Summary of changes:

  c3efb1b... app: don't show invisible actions in search dialog (*)
  53c145c... app: add --show-debug-menu command-line option (*)
  dbb9fdb... Update Catalan translation (*)
  7c1ea03... configure.ac: fix check for freetype2 (*)
  5d83c76... devel-docs: minor typo. (*)
  479bcaa... configure, docs: set correct "mypaint-brush-path" value in  (*)
  8811e31... app: cleaning out some if-0 variables. (*)
  4698529... app: make MyPaint brushes path relative on Win32 and macOS. (*)
  452b1bd... Stop leaking properties of the distcheck machine into the t (*)
  29d7cee... configure.ac: add new option --enable-bundled-mypaint-brush (*)
  347acb1... desktop: add gimp-data-extras.metainfo.xml to .gitignore (*)
  31086ae... Update Polish translation (*)
  2aa4426... app: improvements in code executed a lot while painting. (*)
  7be2d14... app: use gimp_config_writer_string() to output the mypaint- (*)
  4928546... app: align projection update area to coarse grid (*)
  04a798d... app: do not copy needlessly paint_mask GimpTempBuf. (*)
  a3071d2... configure.ac: require babl >= 0.1.45 and GEGL => 0.3.31 (*)
  fd6d493... It's alive! (*)
  33b7d8e... file-open-location: create only one progress bar (*)
  a4b366f... file-open-location: disable widgets only while opening a fi (*)
  019af3d... file-open-location: don't close dialog if no file was opene (*)
  e55c94e... Bug 794854 - Brush color is not added to color history in s (*)
  f586aac... app: use g_clear_foo() in gimp_gegl_procedure_finalize() (*)
  44ce8b4... app: a colon was missing after "Debug Policy" in preference (*)
  62ec483... app: ...and a mnemonic. (*)
  14a054e... app: add a "Filter Dialogs" section to prefs -> dialog defa (*)
  fe932fe... Bug 794826 - Do not default to last used filter settings (*)
  9090a98... app: fix new g_object_ref() warnings in gimp_filter_tool_ed (*)
  6571704... app: save image symmetries in the XCF file. (*)
  e0029d3... Bug 792520 - Image symmetries should be saved: version the  (*)
  c9df2a6... app: do not raise a warning when failing to deserialize sym (*)
  617d0c4... etc: add 4K Ultra HD template and fix DCI 4K. (*)
  15041e8... NEWS: starting the news for 2.10.0. (*)
  f242bf4... appdata: Install appstream metadata to non-deprecated direc (*)
  6501faf... Update Swedish translation (*)
  3c1516e... app: mirror positions 0.0 are accepted. (*)
  d779c13... app: do not edit symmetry variables but properties. (*)
  8a24de6... app: fix dashboard help id. (*)
  ea48b9f... Bug 794356 - Rulers always shown for subsequent image views (*)
  4c041b2... app: allow hiding groups in the dashboard (*)
  da3c96f... app: add "misc" group to the dashboard (*)
  4acdc73... app: use gegl_tile_handler_damage_rect() in TileHandlerVali (*)
  cad72b1... app: remove unused variable in gimp_tile_handler_validate_c (*)
  5e2600d... NEWS: keep up-to-date. (*)
  b46b9d8... Bug 772126 - Make GimpColorFrame handle very long numbers (*)
  bbd79f9... app: fix Wilber's eyes (*)
  cdc20c9... Updated French translations (*)
  de0706f... Updated French translation (*)
  65a697f... app: switch the first two args of gimp_channel_new_from_buf (*)
  7230d5d... Bug 794356 - Rulers always shown for subsequent image views (*)
  33822c5... app: check if tool control is active before setting modifie (*)
  6936a65... plug-ins: minor fix of an error string. (*)
  c462111... libgimp: properly catch SIGABRT signal. (*)
  6bcb30e... devel-docs: update debugging-tips.txt regarding --stack-tra (*)
  e98b937... libgimp: add a gimp_fatal_func() allowing stack tracing plu (*)
  9c8a8ae... libgimp: do not end the fatal and signal handlers with gimp (*)
  76bce77... libgimp: various warning fixes for Win32. (*)
  fa02a2c... libgimp: add an exception handler for Windows. (*)
  394c930... app: avoid potential division by 0 in dashboard CPU usage s (*)
  700cc33... configure.ac: require a C++11 compiler (*)
  86b89cf... app: add gimp-parallel (*)
  565f1f2... app: switch gimpbrush-transform.c to C++ (*)
  c8d4c07... app: parallelize gimpbrush-transform.cc (*)
  e8a14de... app: switch gimppaintcore-loops.c to C++ (*)
  3df757f... app: parallelize gimppaintcore-loops.cc (*)
  828b99b... app: switch gimp-gegl-loops.c to C++ (*)
  cb239e6... app: parallelize gimp-gegl-loops.cc (*)
  ba06a0f... Bug 794949 - Plugin crash when opening png, jpeg or tiff wi (*)
  b88170b... NEWS: keep up-to-date. (*)
  082a640... app: fix iterator area in canvas_buffer_to_paint_buf_alpha( (*)
  0009794... app: migrate tool-presets with s/GimpImageMapOptions/GimpFi (*)
  7aecc90... Remove Lighter, Darker, and Gray themes (*)
  cf21dcb... Rework and rename the default Dark theme (*)
  f7ea9ab... app: add include guards to gimppatincore-loops.h (*)
  6e314b5... app: move brush-core loops to a separate file (*)
  4336e2e... app: parallelize gimpbrushcore-loops.cc (*)
  299a258... NEWS: keep updated (*)
  87b9611... app: fix build error "‘memset’ was not declared in this (*)
  d668399... Updated Russian translation (*)
  f7c2ce9... app: fix smudge tool artifacts (*)
  43549b7... app: remove some references to TileManager from xcf-load.c  (*)
  494f684... build: do not bundle glib anymore. (*)
  d2c4db1... build: upstream flathub build and base modules updated too. (*)
  d907898... build: update dev and nightly flatpak manifests. (*)
  0ae8e35... po: fix desktop file keywords syntax for Basque translation (*)
  2dd2f2f... Bug 770424 - Themes: insensitive menu item are not readable (*)
  81e1e39... app: silence gcc warning (*)
  87a10aa... Bug 795048 - Image->mode->Grayscale results in a black or t (*)
  bea2717... app: throttle statusbar progress updates (*)
  06950be... Makefiles: don't use -xobjective-c when compiling C++ files (*)
  6ebc3f1... Makefiles: don't use -xobjective-c when linking files on Ma (*)
  440be88... Bug 794926 - Foreground select tool: several critical error (*)
  db50c72... app: align display paint area to a coarse grid (*)
  ce9ca03... app: add gimp_drawable_{start,end,flush}_paint() (*)
  8e7a342... app: move painting to a separate thread (*)
  bb4ac7c... Bug 791519 - Unexpected selection from channel (*)
  8994246... Bug 791519 - Unexpected selection from channel (*)
  7fdb963... Bug 794996 - Misc. typo fixes in comments in app/ (*)
  c4975dd... Update Polish translation (*)
  53fae39... Bug 795057 - Insensitive text in plug-ins is unreadable wit (*)
  bb52431... libgimpbase: gimp_stack_trace_*() should get backtraces for (*)
  9dfd35b... build: update base dependencies to fix flatpak. (*)
  ab7c3d2... libgimpbase: oups, I lost the "full" option in my backtrace (*)
  f77edcd... app: do not use gimp_filename_to_utf8() in the signal handl (*)
  2ae16ca... app: reorganize gimppaintool-paint (*)
  e98506b... app: remove option for paint tools to opt out of a separate (*)
  f5cb1fe... Bug 795081 - Crash when using a brush combined with a dynam (*)
  54ca0a7... Add Gray theme back to GIMP (*)
  bba8f69... Revert "Bug 791512 - make the selection boundary detection  (*)
  6effffb... pdb: one of the recent typo fixes was in a generated file (*)
  3f95dc5... Bug 791519 - Unexpected selection from channel (*)
  4bc982b... Bug 795123 - plug-in crash starts neverending loop. (*)
  ae6a7bf... libgimpbase: improve multi-threaded stack traces. (*)
  f81542e... app, cursors: add rotate cursor modifier (*)
  2c1f1c5... app, cursors: add zoom cursor modifier (*)
  634d5ae... app: add GimpToolGyroscope (*)
  8738d2f... app: add a gyroscope controller to prop-gui (*)
  6982533... app: add custom GUI for gegl:panorama-projection (*)
  f6255ae... desktop: changes in appdata and 2.10 <release> now uncommen (*)
  6453b37... app: fix status message of GimpToolGyroscope (*)
  dd77b05... 2.10: updates for appdata (*)
  087d246... configure/app: depend on babl 0.1.46 (*)
  9f55de0... Update Russian translation (*)
  a627d47... NEWS: update (*)
  4b725c6... NEWS: more updates (*)
  0a1dd37... desktop: preparing a new <release> tag for 2.10.0 RC2. (*)
  12ec797... NEWS, desktop: small fixes in NEWS and in <release> appdata (*)
  1993d8a... Bug 768872 - Tiling Symmetry doesn't wrap vertical coordina (*)
  7bb0821... Update Polish translation (*)
  5430e77... app: various fixes in GimpToolGyroscope (*)
  5b8b33d... app: invert zoom mapping in gegl:panorama-projection gyro c (*)
  421c9fc... Bug 795050 - ‘strncpy’ output truncated before terminat (*)
  09b9eab... Merge branch 'master' into meson
  4aefa23... Backport master modifs to meson branch.
  11af20f... Backport LibMyPaint modifications to meson.

(*) This commit already existed in another branch; no separate mail sent