Diplomacy refactor

[UEWBot]

Something about this breaks the unit tests - seems that they're all not found (even the ones that aren't changed)

[UEWBot]

Aha! https://stackoverflow.com/questions/21069880/running-django-tutorial-tests-fail-no-module-named-polls-tests says that there shouldn't be an __init__.py in the visualiser directory, and indeed deleting that does seem to fix python3 ./manage.py test, although there are still some failures - looks like some of the other test imports need changing to reflect the new structure

[jasonmastbaum]

I was updating the imports by iteratively doing manage.py runserver, fixing the file it complained about, repeated until it successfully did the runserver. Good reminder that I need to do the tests too.

[UEWBot]

Yeah, the unit tests are actually quite good at picking up regressions. Definitely useful for this kind of work

[UEWBot]

Finally merged