With numerous circular requires.

I understand that you find the existence of an ob-core file
aesthetically unappealing.  In principle I don't disagree, but in this
particular case I do not see any preferable solution (including the
"keep things as they are" option).  If you can think of a better option
I'm open to suggestions, but if not I would like to commit this change
to master.

Thanks,

-- 
Eric Schulte
http://cs.unm.edu/~eschulte