New g_part class

[Marcel Moolenaar]

All,

I sent a diff to re@ for review, but I figured this is also a good  
place.
The diff can be found here:
	http://mail.xcllnt.net/~marcel/g_part.diff

The g_part class is a generic partitioning class with a rich set of
g_ctl verbs for creating and modifying partition schemes. Currently
only GPT (GUID Partition Table) and APM (Apple Partition Map) are
implemented, but the KOBJ interface makes it easy to add other
schemes like MBR, BSD, SUN and/or PC98.

The diff only contains the kernel part. A userland tool is forthcoming.
A description of the g_ctl verbs can be found here:
	http://wiki.freebsd.org/MarcelMoolenaar

Thoughts and suggestions are welcome,

-- 
Marcel Moolenaar
xcllnt at mac.com