augment USE_GCC description in the porter's handbook

hi, cooked something up, so people would get less confused about proper USE_GCC usage. diff attached. ./danfe Index: book.xml === --- book.xml(revision 42655) +++ book.xml(working copy) @@ -3822,10 +3822,11 @@ /e

Tweaks to the wait(2) manpage

I have some tweaks to the wait(2) manpage, in particular to the sections on wait6() and idtypes. I did also change two other places to use uppercase for ID since that seems to be what we do in other pages. The alternate rendered text is below followed by the diff. One structural change I chos