On to usable sysfs shadow directory support...

The following patchset has been tested on 2.6.21-rc6 + Kay's
driver-core-fix-namespace-issue-with-devices-assigned-to-classes.patch

It has been tested both with CONFIG_SYSFS_DEPRECATED set and
unset.  Although more testing has been involved with CONFIG_SYSFS_DEPRECATED
unset because that was the hard case.

After the change of network devices from struct class_device to struct device
it has taken me a while to figure out how to get the shadow directory support
to actually work in a maintainable race free manner.  I wound up pushing
a lot more of the logic down into sysfs to accomplish this (primarily shadow
directory creation and deletion).  Which radically change the interfaces to
how I work with shadow directories at the upper levels.

So this patchset:

- fixes some aesthetic issues with Kay's patch.
- Rips out almost all of the old shadow directory support.
- Adds new shadow directory support.
- Adds some shadow directory friendly symlink manipulators
- Adds struct class and struct support for shadow directories.

Eric