switching long suffixes to short suffixes

[affeldt-aist]

• odd_add -> oddD
• odd_sub -> oddB
• take_addn -> takeD
• rot_addn -> rotD
• nseq_addn -> nseqD

Motivation for this change

fixes #359

Things done/to do

• added corresponding entries in CHANGELOG_UNRELEASED.md
  - [ ] added corresponding documentation in the headers

Automatic note to reviewers

Read this Checklist and make sure there is a milestone.

[CohenCyril]

@affeldt-aist looks like fourcolour needs an overlay

[pi8027]

Hello. Shouldn't we use the deprecation facility rather than having overlays?

math-comp/mathcomp/ssreflect/ssreflect.v

Lines 15 to 28 in 5d7bd2e

	(* deprecate old new == new, but warning that old is deprecated and new *)
	(* should be used instead. *)
	(* --> Usage: Notation old := (deprecate old new) (only parsing). *)
	(* --> Caveat: deprecate old new only inherits new's maximal implicits; *)
	(* on-demand implicits should be added after : (deprecate old new _). *)
	(* --> Caveat 2: if premises or conclusions need to be adjusted, of for *)
	(* non-prenex implicits, use the idiom: *)
	(* Notation old := ((fun a1 a2 ... => deprecate old new a1 a2 ...) *)
	(* _ _ ... _) (only printing). *)
	(* where all the implicit a_i's occur first, and correspond to the *)
	(* trailing _'s, making sure deprecate old new is fully applied and *)
	(* there are _no implicits_ inside the (fun .. => ..) expression. This *)
	(* is to avoid triggering a bug in SSReflect elaboration that is *)
	(* triggered by such evars under binders. *)

[affeldt-aist]

Hello. Shouldn't we use the deprecation facility rather than having overlays?

Indeed. Will do.