[gtksourceview] (7 commits) Non-fast-forward update to branch wip/undo-redo

[Sébastien Wilmet <swilmet src gnome org>]

The branch 'wip/undo-redo' 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:

  4d0a27c... UndoManager: improve doc
  076256d... UndoManager: update_can_undo_can_redo() utility function
  22f8c84... UndoManager: another batch of code clean-up

Commits added to the branch:

  3f7b4fd... Use css also to apply line numbers colors (*)
  e5bd3c8... Updated French translation (*)
  a43030d... CompletionInfo: remove weak pointer (*)
  7c8de19... UndoManager: more unit tests (*)
  58369ef... UndoManager: improve doc
  7197651... UndoManager: update_can_undo_can_redo() utility function
  28c77ed... UndoManager: another batch of code clean-up

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