Cosmetic changes; some void-safety improvements.
Add a new function to get rid of "!" in "!TYPE" which is now the result of TYPE.name for attached types.
Make property_definition_at_path have an attached result.
Add enable/disable sensitive to EVX data controls.
Add some intelligence to undo/redo, so that when an undo or redo agent is executed, the GUI returns to the visual context where the action was originally performed.