bug#30202: 27.0.50; Code refactoring on assq-delete-all assoc-delete-all

[Eli Zaretskii]

> From: Tino Calancha <tino.calancha@gmail.com>
> Date: Mon, 22 Jan 2018 14:24:38 +0900
> Cc: monnier@iro.umontreal.ca
> 
> yesterday was added (how about to announce it in NEWS file?)

Please just add a NEWS entry if you find a missing one.  Bonus points
for documenting new functions in the respective manual(s).

Thanks.