toggleConfig() via attribute and part of save() (for perspective-viewer)

## Feature Request
When `save()`'ing, I think it'd be nice if there were a `show-config` (or similar) option containing the state of `toggleConfig()`.

### Description of Problem:
Trying to save the full state of a graph for future viewing, but cannot do so easily for the toggled config.

### Potential Solutions:
An ugly workaround is to manage the state myself.
