Interrupting evaluations produces extra output and no prompt

[PEZ]

When interrupting a running evaluation there is no prompt printed in the output window. This indicates that something goes wrong before the prompt is printed.

Also, when interruption something like this:

  (loop [i 100]
    (println i)
    (Thread/sleep 75)
    (if (zero? i)
      i
      (recur (dec i))))

The output is printed once again, only as single line comments.

[bpringe]

The previous fix broke stacktrace output. That was fixed but I forgot to make sure this worked.