[Project_owners] Discarding high scoring spam to lists

[David Boswell]

> I don't think discarding non-member postings is a good idea.

I agree that for many projects this doesn't make sense, but for other
projects this could work fine.  Personally I don't think this is
something we can set globally, unlike other settings which are more
universally applicable (like turning off having a notice sent out every
time a new moderated message comes in).

David