Improved PersistenceUnit/PersistenceContext reference resolution

Reference resolving should support scopes: within the module, then within the ear

When looking for something by @PersistenceUnit or @PersistenceContext and not specifying a unitName, the nearest scope is searched first before checking an outer scope.

Possibility: If a nearer scope has two units, we pick the one listed first in the persistence unit. Will have to check to see if the code will allow this.