Integrate stubgenj somehow

Autocompletion in IDEs via static analysis is awesome. But pyimagej supports dynamically importing any Java class from any Maven artifact. It would be fantastic to add a mechanism, which is as convenient as possible, to generate, for whichever artifact(s) you have imported via jgo, the stubs that go with it. And then point the IDE at it.

@elevans and @hinerm and I are pretty sure we don't want to publish pregenerated stubs for anything, because there is too much, and it changes too often.

Start by reviewing how pyimagej uses jgo to import Java classes from Maven artifacts, then investigate how stubgenj could generate stubs for those imported artifacts. The result should provide a convenient mechanism to generate the relevant stubs and a way to point an IDE at them; no specific files or tests are named.

Written by the indexing model from the issue text.