screenshot-window-sizer: New extension

Originally from hughsie's github[0], but way too useful to leave
in a 3rd party repo :-)

[0] https://github.com/hughsie/gnome-shell-extension-screenshot-window-sizer

https://bugzilla.gnome.org/show_bug.cgi?id=736470
screenshot-window-sizer: Do not translate schema for now

It's not worth a string freeze break, we can revert after the freeze
has been lifted ...
Bump version to 3.13.92

To go along GNOME Shell 3.13.92