[gnome-books] (2 commits) Non-fast-forward update to branch wip/hadess/fix-preview-warnings

[Bastien Nocera <hadess src gnome org>]

The branch 'wip/hadess/fix-preview-warnings' 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:

  9faa5cd... preview: ensure signals/sources are removed upon destroy

Commits added to the branch:

  5ebc13e... preview: ensure signals/sources are removed upon destroy
  9c9193a... preview: use action_name for prev/next buttons