[gnome-todo] (36 commits) Non-fast-forward update to branch wip/sadiq/fixes

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

The branch 'wip/sadiq/fixes' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  fafc1af... window: Remove unused variables

Commits added to the branch:

  78fdf35... build: Introspect the private share library (*)
  24adcd4... list-store: Introduce GtdListStore (*)
  0b7c539... engine: Use GtdListStore (*)
  a01863e... list-model-filter: Introduce GtdListModelFilter (*)
  955546b... task-list-popover: Add filtering to task list names (*)
  4be0347... list-store: Remove Since annotations (*)
  dedc18d... list-store: Introduce gtd_list_store_get_item_position (*)
  d32a16b... task-list: Turn check into assertion (*)
  e08149c... task-model: Introduce GtdTaskModel (*)
  de0940f... manager: Use #pragma once (*)
  70ea3a7... tests: Change model-filter test path (*)
  60d4936... tests: Add a DummyProvider to the test suit (*)
  8daa5ce... manager: Add function to inject GtdProviders (*)
  2d66808... tests: Add tests to GtdTaskModel (*)
  63d3667... manager: Add a task model and supporting API (*)
  305cc29... list-model-filter: Unassorted performance and style improve (*)
  e1f1777... task-model: Fix 'items-changed' signal emission (*)
  92e8e9a... list-model-sort: Introduce sorting model (*)
  d13113d... task-row: Remove a couple of tracing entries (*)
  93cdb13... task-list: Split save_task() into add_task() and update_tas (*)
  b3a8691... panels: Use GtdListModelFilter and GtdListModelSort (*)
  4dd61d2... list-store: Cache length (*)
  7efd200... list-models: Smaller fixups (*)
  20e774d... project: Rename contrib/ to models/ (*)
  a847323... task: Implement GList-less, zero-copy subtask handling (*)
  1dc27f6... task: Reorganize and instrument more code (*)
  859a4ad... task-list-eds: Couple of style fixes (*)
  c75357f... task-list-eds: Don't add subtask if it's already added (*)
  a37e423... task-list: Also add subtasks when adding parent task (*)
  ff5f84c... task-list-view: Brutally simplify task removal workflow (*)
  52f6ae9... list-model-sort: More fixups (*)
  a360c4a... task: Fix total subtask counter update issue (*)
  31b7047... task-list: Recursively add and remove subtasks (*)
  7ede540... manager: Retire gtd_manager_get_task_lists() (*)
  3754b84... task-list: More performance improvements (*)
  692d89d... window: Remove unused variables

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