MFC r315774:

mount.conf(8): fix a .Xr call

Add the missing section number for devfs(5)

MFC r267667:
use .Mt to mark up email addresses consistently (part1)

PR: 191174
Submitted by: Franco Fichtner <franco at lastsummer.de>

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Minor mdoc fixes.

In this GRN, Marcel Moolenaar overhauled the logic for mounting
the root file system on bootup:

|------------------------------------------------------------------------
|r214006 | marcel | 2010-10-17 22:01:53 -0700 (Sun, 17 Oct 2010) | 20 lines
|
| Re-implement the root mount logic using a recursive approach, whereby each
|root file system (starting with devfs and a synthesized configuration) can
|contain directives for mounting another file system as root.
|------------------------------------------------------------------------

This commit adds a mount.conf(8) man page which documents
the root mount logic. mount.conf(8) also provides some examples
for the /.mount.conf file, which can be used to change the root mount behavior.

Reviewed by: marcel bjk