prepare to remove HandleIterator

Its just un-needed, pointless complexity
Start using the new interfaces correctly
Fix crazy circular dependency!
Move some trivial functions into header.

Its hard to tell what the pooint of this class is, when many
of the functions are hidden away (and are just trivial wrappers!)
Add missing include file (fixes build break)
Move trivial functions from C file the header

Its kind of hard to see what the point of this class is,
since many of its methods are just trivial wrappers.
Get rid of one user of the HandleIterator
Final steps to get rid of HandleIterator
Get rid of HandleIterator completely
Remove more badly designed code.
Rename seeveral methods

Give them unique names. This will make radingthe code easier...
Get rid of another HandleEntry user
Remove more HandleEntry using code
Add an iterator to the IncomingIndex
Eliminate another HandleEntry usage
several bug fixes for tests
Another bug fix for recently added code
Misc minor cleanup.
misc cleanup. More de-HandleEntry-ing of code

Just reviewd the PredicateIndex. Looks real good.
More minor cleanup, and some docs