Live deploy as a nightly version

I've added the live deploy option as a nightly version. This future is enabled by setting the "live-deploy-mode" flag to true.

review @devoncarew @ussuri
I should say that the actual usage in the code looked very bizarre to me until I looked up how this singleton worked. I thought you were creating new objects all the time. I'd say a more traditional and explicit way would be preferable, e.g. just `final static LiveDeployManager instance => new LiveDeployManager._();`. Alternatively, you could have an internal `_instance` and make the whole public API of this class static (i.e. `init` and `setCurrentProject`).