Some changes required to enable overriding of the Persistence Service

Scott,

These are some changes I needed to make to override the persistence service with one in a Payara (GlassFish module).

First change is using the ThreadContextClassLoader within ServicesManagerImpl rather than just Class.forName

Second change is exporting more of the APIs from the Manifest as GlassFish is OSGI based I couldn't use the container classes without exporting them.

Third change is to the OSGI bundle names, I changed them to reflect the new maven coordinates. I can change this back if required.

With these changes I have successfully managed to completely override the provided persistence service with a custom one. 

Steve