[meld] (49 commits) ...Merge branch 'pathlabel'

[Kai Willadsen <kaiw src gnome org>]

Summary of changes:

  6b9b54b... melddoc: Pull external file opening helper out to a helper  (*)
  b4bc72d... melddoc: Support gfiles for opening externally (*)
  24d9aed... ui.pathlabel: New widget for displaying paths with some hel (*)
  c911cfa... filediff: Remove unused widget mapping (*)
  60a3960... filediff: Move from GtkToolbar to GtkActionBar for per-pane (*)
  370f5fb... iohelpers: Add new common-parent helper (*)
  b1aa0f2... Update flake8 config (*)
  e353761... ui.pathlabel: Update path display to support cross-pane sum (*)
  3f7eb64... filediff: Add open-folder and copy-path actions to file con (*)
  de2630e... Style and indentation fixes (*)
  089f3c4... ui.pathlabel: Fix custom label support (*)
  8095e1c... ui.pathlabel: Fix summarisation display with root parents (*)
  dd7c401... iohelpers: Break out path formatting helper from pathlabel (*)
  8d89a89... test: Add test coverage for `find_shared_parent_path()` (*)
  afe42e8... test: Add test coverage for PathLabel's path formatting (*)
  b7638b6... ui.pathlabel: Update copyright dates (*)
  06cad6c... Reinstate a flake8 default ignore that was accidentally lef (*)
  9c067f8... ui.filebutton: Simple GtkButton subclass for handling file  (*)
  eac1f60... dirdiff: Move from GtkToolbar to GtkActionBar (*)
  a9223f5... ui.pathlabel: Fix Optional typing (*)
  9e18903... ui.pathlabel: Use the plain descendent file as label when m (*)
  f66974a... filediff: Update to use MeldFileButton (*)
  593b62c... dirdiff: Move pane action bar to use MeldFileButton and Pat (*)
  a087653... dirdiff: Remove remaining GtkToolbar usage in favour of Gtk (*)
  c56ed7e... Give PathLabel widgets flat button styling (*)
  a01bb00... pathlabel: Make path label popover use text instead of imag (*)
  6104018... test: Add coverage for shared parent being the root (*)
  2740673... iohelpers: Update label formatting for having a single dire (*)
  0bd2d0d... ui.pathlabel: Support an additional icon in the PathLabel b (*)
  d16bafa... filediff, dirdiff: Add generic icons to label buttons (*)
  1a0277d... pathlabel: Fix label -> text entry spacing (*)
  8102e89... Merge branch 'master' into pathlabel (*)
  386368b... ui.filebutton: Support passing through the local-only file  (*)
  15e8fec... recent: Handle bad comparison metadata cases (*)
  f182716... meldwindow: Don't try to set the VC location if it's missin (*)
  28bbd68... vcview: Rename Update action to Pull (*)
  4a902ee... Add pull and push icons for VC usage (*)
  72d927a... vcview: Move toolbar to actionbar and rearrange action butt (*)
  c516da8... Remove now-unused meld-notebook-toolbar CSS class (*)
  5ac4946... Remove tab labels from app title (*)
  d24e0fe... pathlabel: Fix residual image-buttons in dialog (*)
  b9efb67... Rework open/path label UI arrangement (*)
  057130c... pathlabel: Improve label display in popover (*)
  d09780f... vcview: Remove Update from the VC context menu (*)
  dfd0f14... vcview: Rename resolve action for clarity (*)
  1939da0... pathlabel: Format paths as home-relative where sensible (*)
  357518f... vcview: Reposition VC selection combo to the right of the a (*)
  4ef740a... vcview: Rework VC action bar buttons (*)
  f347734... Merge branch 'pathlabel'

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