AREPL does not restart python if user closes it

[Almenon]

Replication steps:

1. import turtle;turtle.forward(100)
2. exit out of turtle
3. Error logged to dev console: Uncaught Error: process exited with code 3489660927 in python-shell line 89
4. If user types in anything at this point it results in Uncaught Error: this socket has been ended by the other party at PythonShell.send
5. User tries to restart with F1
6. "pyshell refused to die" is logged, followed by "the python process simply cannot be killed!" (the code misinterprets what is happening here - it doesn't realize process is already dead)
7. Because the process has already exited the exit event is never called so the listener for exit does not restart the process

[Almenon]

Havn't debugged it yet but I'd bet that I just need to check if the process is already dead before I try to kill it in the stop() command.

This will need to be fixed in the backend.