Add namespacing and lazy rendering

Had shitty namespacing, i.e., NONE, until now. View panel states are
now exposed through the `states` property.

Rendering at each step of a chain sequence can become expensive (oh
really now?) so I put in a `chain()` method to be called at the
beginning of a chain. Then, do some stack manipulation. Finally call
`render()` in the end to apply the changes to `states`.