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)

All cosmetic.
1) Rename RANDOM_MAX to RANDOM_MAX_PLUS1 to not confuse with random()'s max
2) Use calloc() instead of zeroing fields explicitly
3) "too many lines" -> "too many delimiters" for err()

I was confused a bit by the wrong construction with RAND_MAX
used in randomize_fd.c.
Although the max value is the same currently, RAND_MAX is for rand(),
not for random().
So move RANDOM_MAX const to the common file now, make it UL and
use in randomize_fd.c too.
(in any case its old value was 1 less then must be, as noted in
the prev. commit)

flexlint rears its head as well as some style(9) fixes[1]. Fixed a
few bugs for a few corner cases and correctly handle the case where
read(2) is read()'ing from a non-file descriptor and could get fewer
bytes back than the buffer, but it isn't EOF[2]. random(6) extensively
tested and believed to be bug free (save performance for large files).

Submitted by: mkm [1], tjr[2]

Update random(6) to have the ability to randomize a file/stdin based
off of lines or words. See the man page for details.

Reviewed by: markm
MFC after: 3 days