Catch errors in whisper process

[harrislapiroff]

Currently (on the improvements branch) if the whisper process crashes the spinner seems to keep going. It should instead display an error so a user doesn't wait forever for completion.

(Wanted to make a note of this now, because we'll probably fix the process crashing issue I'm having and then we might forget to handle other errors)

[oenu]

100%, right now error handling states are in but not hooked up to interface