meta: Preferred patch submission policy

[Christoph Biedl]

Julien ÉLIE wrote...

> Your patches are very much welcome.  Thanks in advance for them.
>
> As a side note, cleanfeed and PyClean filters may also be worthwhile
> improving (but are outside the scope of INN).

Thank you. As usual, other things kept me from continuing in
a timely manner.

Just one point about cleanfeed: It defines a function "read_file", and
that brought strange behaviour when adding code that peruses File::Slurp
which defines a function with that same name. Renaming the first to
"cleanfeed_read_file", also the invocations, helped.

    Christoph