Fix bug in bounded int/float logic.
Added test
Fix infinite loop typo
Fix notify_trait getting called too early.
Handle 'deletable' cell metadata
Add tests for undeletable cells
Make cell be undeletable ONLY when metadata is explicitly false
Fix tests
Handle NoSuchKernel errors more gracefully
Show the user a different notification
Report the exact error that occurred
Remove 'we' from message
Better user experience when kernel isn't found
Use 501 error code instead of 400
Return a proper JSON object
Always show the modal dialog, and have a fallback generic message
Don't pop up modal dialog
More descriptive short message
s/long thing/set_state
s/_handle_receive_state/set_state in tests too