OF-859: Pubsub fix; misc cleanup

This fixes a problem with a static final reference in the Node.class. It
also addresses a couple of minor issues discovered during pubsub
testing:
- PubSubPersistenceManager should return an editable collection rather
than a read-only collection for published items
- SequenceManager defaults should use a blocksize of 5 for frequently
used tables
- LocaleUtils should catch and log a MissingResourceException and return
the key in lieu of the missing value (by convention)