* doc/bugreport.texi, doc/configterms.texi, doc/contrib.texi,
doc/contribute.texi, doc/cpp.texi, doc/cppinternals.texi,
doc/extend.texi, doc/install.texi, doc/invoke.texi, doc/md.texi,
doc/portability.texi, doc/tree-ssa.texi, doc/trouble.texi: Avoid
some first-person references and patronizing comments. Based on
printed manual.
* doc/invoke.texi: Don't reference fortran@gnu.org.
* doc/trouble.texi (Warning when a non-void function value is
ignored): Rewrite. From Russ Allbery and Chris Devers.
From-SVN: r84034
