In order to avoid misunderstandings, the term 'genus' was removed in the documentation. Actually, in terms of topology this expression even seems to be wrong for the additive case!

CC: @egourgoulhon @tscrim

Component: geometry

Keywords: characteristic classes, vector bundles

Author: Michael Jung

Branch/Commit: a94b358

Reviewer: Varenyam Bakshi

Issue created by migration from https://trac.sagemath.org/ticket/28854