Propagate status changes to child records.

Since nested records are now being properly unregistered, the status of
nested records was getting stale, leading to exceptions because the status
was still set to SC.Record.EMPTY.
Skip handling drag events on draggable panes if the target of the event
has indicated text should be selectable.
Fixes a regression with SC.CollectionView that occurred after a previous fix to remove a view DOM leak.  SC.CollectionView previously created a view with the same layerId as the view to be replaced before replacing it, which only worked because of some weird logic external to the CollectionView that used to prevent a view from being able to find its layer if it didn't have a parentView (which was also the cause of a leak because the layer might still exist in the DOM).  In any case, having two views use the same layerId at the same time is a bad idea.

So instead we essentially use removeChild().insertBefore() rather than insertBefore().removeChild() (i.e. replaceChild()).
Modified unregisterChildFromParent so it can safely be called on any
storeKey, even if it is not a child record.
Set owner of view when inserting it into a new parent.
More memory leak fixes.
Bumping to SC 1.9.0.7.