Implement sly-stickers-fetch-and-replay

* contrib/sly-stickers.el (sly-stickers): Consider `sly-stickers-shorcut-mode'.
(sly-stickers-enable): Fix indentation.
(sly-stickers-shortcuts-enable): New function.
(sly-stickers-shortcut-mode-map): New map.
(sly-stickers-shortcut-mode): New minor mode.
(sly-stickers--stickers): Make a connection var.
(sly-stickers--sticker,sly-stickers--arm-sticker)
(sly-stickers--bring-out-yer-dead)
(sly-stickers-fetch-all-and-forget): `sly-stickers--sticker' is a
connection var.
(sly-stickers-fetch-and-replay): Implement primitive version.
(sly-stickers-fetch-all-and-forget): Tweak zombie message.

* contrib/slynk-stickers.lisp (recording): Store sticker in
recording.
(initialize-instance): Store recording in sticker and global var
after making it.
(sticker): Store ID in sticker.
(call-with-sticker-recording): Just MAKE-INSTANCE and let
INITIALIZE-INSTANCE take care of the rest.
(next-index-and-recording): New helper.
(visit-next): New slyfun.
(fetch-and-forget): Call FETCH and FORGET.
(fetch): New slyfun.
(forget): New slyfun.