PERFORCE change 118226 for review

[Julian Elischer]

Marko Zec wrote:

> 	
> 	- pf can now be kldloaded, but is not virtualized (yet)

I was thinking that the following might be an interesting 
way to think about  modules..

kldloading a module is 2 parts..
1/ loading it in to memeory
2/ linking it in

In the base vimage you do both, but in the others,
then you only can link in modules that are already loaded.

i.e.  each vimage is responsible for linking the modules that it needs (?)

loading a new module to memeory doesn't mean that the functionality is 
automatically available for all existing vimages...

child images do not inherrit all the linked modules of the parent.. 
they need to link in those they need.