Revision 160210

I'm almost done here.

Fixup the vhost example.

Fix comments in the main config.  In particular, move the User/Group
directive out of the "You can override this in a vhost" section.
(That was probably a legacy of the days when User/Group was used
inside a vhost for suexec.)  Remove the "Action" examples,
which didn't really provide enough information to make any use of
those directives.  And overall cleanup.