square/picasso — pull request #725 by aldenml (2014-10-28 16:23:38+00:00)
Title: Shutdown of thread pool inside Dispatcher only if it is a PicassoExecutorService

If I want to provide an external thread pool, I don't want picasso have the shutdown operation on it.
Also changed the tests to reflect the fact that you can have an internally created or externally provided thread pool.