[osis-core] annotateWork and annotateType

[Harry Plantinga]

After adding annotateWork and annotateType references,
we got into a big discussion about where to put work 
identifiers, osisIDs, etc., which resulted in the current
approach.

However, annotateWork now identifies the location in a
work, not just the work itself.  Would it be better 
named something like annotateRef, since it is of type
osisRef?

Also, I recall seeing the attribute name "bohu" in some 
message some time ago, but I don't recall what it meant.
I find that it suggests nothing to my mind except perhaps 
the sound made after a minor injury to a child's knee.
What does it mean, and is that the best name?

-Harry