This separates the role of the ViewFactory from the ViewRegistry.
The ViewFactory creates *new* views. The ViewRegistry maintains a
persistent 1:1 mapping from models to views, and is owned by the
workspace rather than being a global service. If someone wants to
*create* a view, they use atom.views.createView. If someone wants to
get the workspace’s view element for a given model, they call .getView
on the workspace.
Nathan Sobo
1e6e724be7