Fix up manual page

[vonbrand]

Some fishy 'roff in there.
Again, git patch renamed .txt to appease Github.
0004-Minor-fixes-to-nuweb.1.patch.txt

[vonbrand]

Oops, fixed just the generated file. Corrected here. Also document the -l flag.

0004-Minor-roff-fixes-to-nuweb.1.patch.txt
0005-Document-the-l-flag.patch.txt