[gtk] (74 commits) ...Merge branch 'kill-containers' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  d7b1ecd... Cosmetics: Replace GtkContainer in an error message (*)
  af19c72... button: Fix accessible implementation (*)
  840a5e3... listboxrow: Fix the accessible implementation (*)
  cca73c4... combobox: Fix accessible implementation (*)
  ce5b51b... flowboxchild: Fix accessible implementation (*)
  2e615d8... frame: Fix accessible implementation (*)
  a65f70a... popover: Fix accessible implementation (*)
  295c559... scrolledwindow: Fix accessible implementation (*)
  7fac7c2... statusbar: Fix accessible implementation (*)
  501eda2... window: Fix accessible implementation (*)
  a7abb39... Fix a leftover list box child (*)
  d62ad4e... Fix a leftover window (*)
  e516616... textviewchild: Don't leak children (*)
  84632b0... dragicon: drop gtkcontainer.h include (*)
  aeef59f... textview: Derive from GtkWidget (*)
  52b1a34... treeview: Stop using container api (*)
  3697c57... treeview: Derive from GtkWidget (*)
  c0f0906... actionbar: Add gtk_action_bar_remove (*)
  e2b23e8... actionbar: Derive from GtkWidget (*)
  6b80d90... expander: Add a child property (*)
  1afc749... Use gtk_expander_set_child throughout (*)
  825e98d... expander: Derive from GtkWidget (*)
  253a39c... iconview: Derive from GtkWidget (*)
  fc9873e... paned: Drop some dead code (*)
  bc6643f... paned: Redo the api (*)
  78d20b9... infobar: Add gtk_info_bar_remove_action_widget (*)
  12ca08c... infobar: Add gtk_info_bar_add/remove_child (*)
  bd843ac... Use gtk_info_bar_add_child throughout (*)
  1a33278... infobar: Derive from GtkWidget (*)
  5cda824... grid: Add gtk_grid_remove (*)
  932aa58... Avoid container api on grids (*)
  c065729... grid: Remove a test for grid container functionality (*)
  3852661... grid: Derive from GtkWidget (*)
  96d7074... fixed: Add gtk_fixed_remove (*)
  0d57abf... Stop using container api on GtkFixed (*)
  741a9cb... fixed: Derive from GtkWidget (*)
  5e0c1e6... stack: Add gtk_stack_remove (*)
  01c3e2c... Don't use container api on GtkStack (*)
  ee5587d... shortcutssection: Stop using container api (*)
  b490800... shortcutswindow: Stop using container api (*)
  a7769c9... treepopover: Stop using container api (*)
  5907ece... stack: Derive from GtkWidget (*)
  2f7f6e6... flowbox: Add gtk_flow_box_remove (*)
  3bff7d3... Stop using container api on GtkFlowBox (*)
  ddcc9db... flowbox: Derive from GtkWidget (*)
  5c34b30... textview: Fix popover use (*)
  bf543e0... text: Fix popover use (*)
  47139bc... textviewchild: Derive from GtkWidget (*)
  001d623... customlayout: Cosmetics (*)
  7af15ae... buildable: Cosmetics (*)
  ff91ce9... listbox: Add gtk_list_box_remove (*)
  8814110... Don't use container api on GtkListBox (*)
  c55aa7e... testsuite: Redo listbox sort test (*)
  6f170a0... testsuite: Fix listbox tests (*)
  3d100ab... listbox: Derive from GtkWidget (*)
  d59d9d4... headerbar: Add gtk_header_bar_remove (*)
  abfa4d4... Stop using container api on GtkHeaderBar (*)
  c7b7d78... headerbar: Derive from GtkWidget (*)
  0daa1f3... Stop using container api on GtkNotebook (*)
  a043762... notebook: Derive from GtkWidget (*)
  665edcb... box: Add gtk_box_append/prepend/remove (*)
  2a24b8c... Replace most remaining uses of container api (*)
  537d211... shortcutsgroup: Drop container bits (*)
  58a88a8... shortcutssection: Drop container bits (*)
  6c78eee... dialog: Remove code that doesn't work anymore (*)
  6bc4446... assistant: Remove code that doesn't work anymore (*)
  5f642f8... box: Derive from GtkWidget (*)
  5573a34... Drop gtkcontainer.h includes (*)
  e706d48... testsuite: Drop a container api use (*)
  5ebd42d... Drop GtkContainer and its accessible implementation (*)
  f72d672... dialog: Remove an unused struct (*)
  7ef173a... dialog: Firm up handling of action widgets (*)
  848a8a7... docs: Update migration guide (*)
  82823da... Merge branch 'kill-containers' into 'master'

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