[gedit] (7 commits) Non-fast-forward update to branch wip/panels-as-stacks

[Steve Frécinaux <sfre src gnome org>]

The branch 'wip/panels-as-stacks' 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:

  afe3719... Reimplement GeditPanel in terms of GtkStack instead of GtkN

Commits added to the branch:

  dc760fd... app: check the window is actually a GeditWindow (*)
  277bba7... ViewFrame: more robust code when using the start_mark (*)
  a709473... ViewFrame: delete start_mark when the search box is hidden (*)
  21f5bc6... Added directive to support translations in AppData file (*)
  4e1e584... filebrowser: Fix the icons of the buttons in the toolbar in (*)
  abbcbd3... Reimplement GeditPanel in terms of GtkStack instead of GtkN
  0366b44... Implement a new GeditMenuStackSwitcher widget.

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