Added a dependency from dal.impl to the datasource.  Not ideal but there...

...'s no way to make the reference to osgi service in persistance.xml optional.  This avoids the GracePeriod errors when bundles get updated.  Moved bundles into features file too so that fabric:watch can monitor them and update container when they change.

A colleague is using this example and I offered this workaround to avoid the GracePeriod error.  PR submitted if you'd like to included it.