[gnome-todo] (39 commits) ...task-list-view: fix custom sorting function

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

Summary of changes:

  013e9e7... task: add subtask support (*)
  ed8b1cd... provider-eds: remove task list from internal storage (*)
  7157d48... task-list: proccess subtasks (*)
  2bbfeda... task-row: simplify xml file (*)
  4ba0f78... task-row: implement subtasks with DnD (*)
  13c79ac... task: add ::is_subtask() API (*)
  54ba34c... task-list: emit ::list-changed whenever a task changes (*)
  64bff26... task-list-view: sort listbox when list changes (*)
  50c6e82... task: add ::depth property and API (*)
  c67a54b... task: consider subtask tree when sorting (*)
  ac40bcb... task-row: forbid making a parent task a subtask of a subtas (*)
  fa6b8ff... dnd-row: introduce GtdDndRow (*)
  83a7bca... task-list, task-list-view: manage drag and drop with GtdDnd (*)
  38c93e0... task-row: make better dnd icons (*)
  3bb671c... dnd-row: improve the behavior when moving DnD (*)
  b6619f5... dnd-row: remove unused API (*)
  eb0bb68... task-list-view: delegate DnD to GtdDndRow (*)
  cf839dc... theme: fine tune the Drag n' Drop row (*)
  0951851... task-list-view: consider subtasks when removing a task (*)
  840fbd6... task: fix typo (*)
  2da4297... task-row: properly disconnect from the task (*)
  fe4fe22... task: correctly check stop condition (*)
  97a6c2c... theme: more adjustments to the dnd row (*)
  3d5651a... task-row: scale and render an even better dnd icon (*)
  022715a... grid-item: consider the depth of the task when creating the (*)
  ce6beba... dnd-row: ignore show_all() calls (*)
  4fb2fdd... task-list-view: add ::handle-subtasks property and API (*)
  5c10ea0... today, scheduled: don't handle subtasks (*)
  70ec485... task-list-view: reset dnd row when changing list (*)
  4e88cd2... task-list-view: more improvements on dnd handling (*)
  faa9cd6... task-list-view: avoid flickering when dragging row (*)
  dc88241... task-list-view: make the listbox cover the entire height (*)
  72e8b9a... task-list-view: simplify the drag-motion code (*)
  8770e0f... task-list-view: make the listbox the drag target (*)
  db0daf2... task-list-view: simplify complete task management (*)
  7e211e6... task-list-view: simplify subtask management (*)
  ee0cad5... task-list-view: fix handling of completed tasks (*)
  6a09d92... task-row: properly align rows that doesn't handle subtasks (*)
  25a5405... task-list-view: fix custom sorting function

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