Check in our new doc framework.

Check in our new doc framework.

It still needs to be cleaned up more and some new features from
NetBSD doc project brought in; I really admire the fancy header
system they for their NetBSD Guide.

As of now, the doc framework is clean and very featureful.

The base layout and some files were taken from the FreeBSD doc project
and have been significantly cleaned up and issues have been resolved:

	* Clean integration with a WWW tree, without destroying
	  URIs in generated DocBook documents.

	* Compact directory layout, efficient for mirrors.

	* Support for custom XSL stylesheets and non-DocBook XML.

This needs to be committed now so that future changes by me and others
can be version tracked.

To give others a kick start, I am committing an article outlining
individuals who have contributed to DragonFlyBSD; a Task-List article
which uses custom XSL stylesheet and non-DocBook and the FreeBSD
Architecture Handbook.

The checked-in FreeBSD Architecture Handbook is a starting point for
structuring kernel internal documentation for DragonFly for future
and also for a DragonFlyBSD User/Admin Guide.

Discussed with: 	Matthew Dillon <dillon@backplane.com>