Issue #750

Issue #750

Mockito now errors if a mock is unnecessary, plus a few other minor
API changes.

This is just an IntelliJ refactor, using EventBus in place of
DMDircMBassador whenever possible.

Stop swimming against the tide and accept what most of the rest of
the world does.

While it adds an annoying depth to the actual source code, it makes
the root directory nicer (no more 'test-res' dirs), means we don't
have to override the gradle config, and makes it nicer to work in
IDEA 2016.1.

Java 8 introduces a sane API for dates; to store datettimes
we should now be using LocalDateTime.

This saves getting the FS and suffering the barrage of warnings
related to auto-closeable resources.

This means each test doesn't have to set it up and tear it down
manually (although only one actually did bother to tear it down :)).

This is a little bit icky, but I can't see a nicer way to do it.