bug#43944: 28.0.50; Update modus-operandi, modus-vivendi themes to v0.13.0

[Stefan Kangas]

Protesilaos Stavrou <info@protesilaos.com> writes:

> With regard to British English, there is more of it in the *.el files I
> shared: "colour" probably is the most common one.  Shall I prepare a
> patch?

Sure!  Or it could wait until you release the next version, if you
prefer that option.