Manual grading after interrupted kernel

[adibaba]

Expected behavior
After executing nbgrader autograde, and exceeding the ExecutePreprocessor.timeout value (default:30), the kernel is interrupted.

Now, a manual grading should be possible.

Actual behavior
The Formgrader extension displays needs autograding.

Opened nbgrader issue: jupyter/nbgrader#1033

[adibaba]

Exception issues may concern the iJava kernel.
Maybe related to #9 Validation.

[adibaba]

Autograding works. (Also uses Exceptions.)