literal name_enable wherever possible, and ${name}_enable
when it's not, to prepare for the demise of set_rcvar().
In cases where I had to hand-edit unusual instances also
modify formatting slightly to be more uniform (and in
some cases, correct). This includes adding some $FreeBSD$
tags, and most importantly moving rcvar= to right after
name= so it's clear that one is derived from the other.
KEYWORD: FreeBSD scourge. We have ignored this keyword
for a long time now, so this is a non-functional change
(therefore no PORTREVISION bumps).
Insert a $FreeBSD tag where needed, and adjust a comment
in mail/milter-regex to match reality.
