- Pass in ID
- Don't burst the full backbuffer

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.

These will be going away shortly.

This adds an 'initial state producer' to create the burst of
state clients will receive on connect, and serialisers for
WindowModels and BackBuffers.