related events from within the model handling code. The only
exception to this currently is item_created which is challenging
because we have to save the item using ORM_MPTT::add_to_parent()
before the object itself is fully set up. When we get that down to
one call to save() we can publish that event from within the model
also.
1) The item_updated event no longer takes the old and new items.
Instead we overload ORM to track the original data and make
that available via the item. This will allow us to move event
publishing down into the API methods which in turn will give us
more stability since we won't require each controller to remember
to do it.
2) ORM class now tracks the original values. It doesn't track
the original relationships (no need for that, yet)
3) Added new events:
item_deleted
group_deleted
user_deleted
* Create Exif_Record_Model to track whether we've scanned the EXIF
data for this photo or not. This allows us to track photos that
don't have EXIF data (and won't have any Exif_Keys)
* Blow away old Exif_Keys when extracting, else we hit unique
index constraints.
* exif::_get_stats() -- before it was running the task forever
