Review - 15505 convert cstyle.ms to mdoc

Review - 15505 convert cstyle.ms to mdoc

[Andy Fiddaman]

Hello,

I would like to upstream an mdoc conversion of "C Style and Coding Standards
for SunOS" that we have been using at Oxide to help people new to working on
illumos code.

This is a relatively faithful conversion of the original, with some amount of
additional text and clarifying examples, and a couple of new sections to reflect
current practice with regard to some C99 features that are used in gate.
This version version should reflect the style we are already using today
and will hopefully not be too controversial, although any style is necessarily
a compromise!

The original source document can be found as an attachment to the issue at

    https://www.illumos.org/attachments/2281

and I've put a rendered version of the man page at:

	https://man.omnios.org/tmp/style.7.html

Please can you review:

    15505 convert cstyle.ms to mdoc
    https://www.illumos.org/issues/15505
    https://code.illumos.org/c/illumos-gate/+/3374

Thanks,

Andy