Crog/jpa config update

A new PR against master instead of old gutterball-hibernate branch.

Old PR is #750
I don't feel like `toMap()` is necessary since we control `JPAConfigParser` entirely.

How about instead of stripping the namespace in `CandlepinModule` or `GutterballModule` (which I agree is a little confusing), we strip the namespace internally within JPAConfigParser?  That way all the details are encapsulated in the one class.

Something like this in JPAConfigParser would probably do it.

```java
public Properties readConfig(Configuration inputConfiguration) {
  Properties p = inputConfiguration.getNamespaceProperties("jpa.config");
  return super.parseConfig(p);
}
```