(SEMANTIC CHANGE) update-objects-joins now simpler and more predicatble

(SEMANTIC CHANGE) update-objects-joins now simpler and more predicatble

The previous default was to update only :deferred slots but the
docstring *said* it was doing :immediate slots.

The new default is to do :immediate slots which was the specification,
and provides some consistency with the rest of the system which
defaults to only operating on :immediate slots.

New behavior for SLOTS parameter:
 * :immediate (DEFAULT) - refresh join slots created with :retrieval
   :immediate
 * :deferred - refresh join slots created with :retrieval :deferred
 * :all,t - refresh all join slots regardless of :retrieval
 * list of symbols - which explicit slots to refresh
 * a single symobl - what slot to refresh

 * :immediate - refresh join slots created with :retrieval :immediate
   (the default)
 * :deferred - refresh join slots created with :retrieval :deferred
 * :all,t - refresh all join slots regardless of :retrieval
 * list of symbols - which explicit slots to refresh
 * a single symobl - what slot to refresh

Readability improvements:
 * split into a couple functions instead of one giant one.
 * standardize on loop instead of many different iteration constructs