[gtk] (10 commits) ...Merge branch 'tabular-menus' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  e2693ef... testgtk: Drop tabular menu (*)
  19dbc83... Drop row/column-span-column from tests (*)
  f87e40b... Drop a grid combo example (*)
  b3dbdcd... fixup notify tests (*)
  b0e67f1... testcombo fixup (*)
  a5ba0d4... combobox: Drop support for grids (*)
  a65f5c2... tree menu: Drop support for grids (*)
  e31a961... Drop gtk_menu_attach (*)
  9dee863... menu: Drop the child properties (*)
  a380129... Merge branch 'tabular-menus' into 'master'

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