[LSC] BFC Standard - Revision 1

[William Howard]

I've updated the BFC standard following our discussions.

The new version is here
http://www.ldraw.org/index.php?name=News&file=article&sid=408

The draft spec is here
http://www.ldraw.org/modules.php?op=modload&name=News&file=article&sid=217

As suggested by Travis, I have changed all occurances of "clipping" to
"culling" in the descriptive text, and added a comment about keeping CLIP
and NOCLIP for backward compatibility

I've also changed the syntax section as per the discussions.

I've removed the empty "Guidelines for Part and Primitives authors" - if we
want to make suggestions then I think we would be better "sponsoring" some
of the tutorials that have been posted to lugnet.cad on this topic

I've also removed all but one of the "current issues" as these have now been
addressed.  The last remaining issue needs to be addressed before the
standard is ratified, but someone else will need to re-word any sections
that this applies to, as it's not entirly clear to me what it's getting at.

I've also made various minor changes to make some things more explicit
(CERTIFY/NOCERTIFY once only and at the top of the file, changing of winding
direction within the file, etc), to improve general readibility and to
improve the logical flow of the text.

Apart from moving the "Parts Library Guidelines" section above the
"Rendering Engine Guidelines" section I have made no changes to either of
these sections or to the final "Rendering Processing" section.