Given people are now using the library, I think we should follow proper lifecycles for our methods. In this case, we should keep the old `oneway(X source, Y target)` methods, but mark them as deprecated (I think there's an annotation which will generate warnings during build?).

The `oneway(source, target)` methods would generate the relevant Push/PullReplication object, then call oneway with that object.

The Java URI manipulation methods should allow us to extract creds from the URIs easily enough.