[libepc] (17 commits) ...gtk4: examples: Replace GtkHButtonBox.

[Murray Cumming <murrayc src gnome org>]

Summary of changes:

  a1516a7... Change ABI from libepc-1.0 to libepc-2.0 (*)
  803b947... Use gtk+-4.0 (and avahi-ui-gtk4) instead of gtk+-3.0. (*)
  f462815... libepc-ui: Replace deprecated gtk_image_new_from_stock(). (*)
  6c8d38b... libepc-ui: Replace deprecated GTK_STOCK_*. (*)
  986730b... libepc-ui: Replace deprecated gtk_misc_set_alignment(). (*)
  16221f9... libepc-ui: Replace deprecated gtk_vbox_new(). (*)
  f1d0dc5... gtk4: Replace gtk_container_set_border_width(). (*)
  4b37b23... gtk4: Adapt to changed gtk_box_pack_start(). (*)
  151c318... gtk4: Replace GtkTable with GtkGrid. (*)
  e9be98c... examples: Replace deprecated GtkVBox, GtkHBox and GtkHPaned (*)
  1d64a22... example: Replace deprecated stock-id (*)
  551ec11... examples: Avoid removed border_width. (*)
  43e0f19... gtk4: examples: Replace GtkAlignment. (*)
  21bbecb... gtk4: examples: Replace GtkTable with GtkGrid
  f6ca1e5... gtk4: examples: Replace another GtkAlignment.
  46404fe... gtk4: examples: Remove has_separator property
  8f40874... gtk4: examples: Replace GtkHButtonBox.

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