bug#26500: [PATCH] gnu: Add mcomix.

[Arun Isaac]

> No, I think a short comment behind or above the #:python keyword is
> necessary, in case someone in the future wonders "Hey, why do we package
> this for python 2 only and not for python 3" even if both languages are
> developed in parallel.

Ok, it doesn't hurt to keep the comment. Let's keep it.

> +    (description "A customizable image viewer that specializes as
> +a comic and manga reader.  It supports a variety of container formats
> +including CBR, CBZ, CB7, CBT, LHA.
> +For 7z support install the p7zip package.
> +For rar support install the unrar package.
> +For pdf support install the mupdf package.")

Instead of mentioning p7zip, unrar and mupdf in the description, it
would be better if we could make them inputs and patch all references to
the executables in the source with their absolute paths. Could you try this?