Fix skeletons in comp(1), forw(1) and dist(1)

Fix skeletons in comp(1), forw(1) and dist(1)

While I was here, I removed two 'empty' paragraphs (.PP) in forw(1).
They may have been intended as line breaks, but I think they are
unnecessary; feel free to overrule me!

Aside: I would not be unhappy if, some day, 'skeleton' was replaced by
something utilitarian like 'template'.