Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

mdoc: order prologue macros consistently by Dd/Dt/Os

Although groff_mdoc(7) gives another impression, this is the ordering
most widely used and also required by mdocml/mandoc.

Reviewed by: ru
Approved by: philip, ed (mentors)

Mechanically kill hard sentence breaks and double whitespaces.

Mdoc Janitor:

* Fix hard sentence breaks.

mdoc(7) police: scheduled sweep.

Approved by: re

Slight overhaul of arc4random() and friends.

One bug fixed: Use getmicrouptime() to trigger reseeds so that we
cannot be tricked by a clock being stepped backwards.

Express parameters in natural units and with natural names.

Don't use struct timeval more than we need to.

Various stylistic and readability polishing.

Introduce arc4rand(void *ptr, u_int len, int reseed) function which
returns a stream of pseudo-random bytes, observing the automatic
reseed criteria as well as allowing forced reseeds.

Rewrite arc4random() in terms of arc4rand().

Sponsored by: DARPA & NAI Labs.

Update the prototype for read_random to reflect that the count parameter
is an int not an unsigned int, and that it returns an int not an unsigned
int.

mdoc(7) police: Use the new .In macro for #include statements.

mdoc(7) police: remove extraneous .Pp before and/or after .Sh.

mdoc(7) police: normalize .Nd.

Sort NAMES section and separate Nm arguments from trailing punctuation.

Add a man page for part of the PRNG API.