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

Remove trailing whitespace.

The ad(4) driver no longer exists in FreeBSD CURRENT or 9, so change the
references to it in gsched(8) to the existing ada(4) driver.

PR: docs/170085
Submitted by: olgeni
Approved by: gavin
MFC after: 5 days

Remove superfluous paragraph macro.

Remove reference to gsched_as module, which doesn't
actually exist.

PR: docs/163043
Submitted by: olgeni
Approved by: brd
MFC after: 3 days

gsched(8): fix example usage, mdoc nits

- ad0 was referred to as da0
- wrong parameter -s instead of -a in example
- use double quotes consistently

PR: docs/150082
Submitted by: N.J. Mann <njm@njm.me.uk>
MFC after: 2 weeks

gsched(8) was first released with FreeBSD 8.1

MFC after: 3 days

mdoc nitpicking for gsched.8
- remove stray argument [1]
- remove stray whitespace
- use canonical wording for the HISTORY section

PR: docs/147119 [1]
Submitted by: Alexander Best <alexbestms@wwu.de> [1]
MFC after: 1 week

fix copyright format, as requested by Joel Dahl

Bring in geom_sched, support for scheduling disk I/O requests
in a device independent manner. Also include an example anticipatory
scheduler, gsched_rr, which gives very nice performance improvements
in presence of competing random access patterns.

This is joint work with Fabio Checconi, developed last year
and presented at BSDCan 2009. You can find details in the
README file or at

http://info.iet.unipi.it/~luigi/geom_sched/