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.
* Fix %m GNUism in printf.
* Don't create the man page, it is already included.
* ptpd is not a user command, put it into sbin.
* Overhaul the startup file and move it to "ptpd".
Approved by: gnn (maintainer)
