status update
Backing store performance optimization
Make use of the new ignore list
Cleanup AtomSpaceIml, mostly documentation

Also clarify semantics of some of the methods.
Minor performance optimization for NLP pipeline.
Shuffle around NLP atom types

These atom types, used to be used by RelEx, but are obsolete,
and so are removed. However, embodiment *also* uses them, but
in a completely different way. So move these over to be
embodiment-only atom types.
Performance hack for language processing.
Remove frame stuff from unit tests.

Some of the unit tests used the obsolete frame types.  Remove
these, and replace with other random types.
Bug status update
Add an explicit write barrier to the API