As UI/UX improvement, try and avoid printing an extended traceback if...

As UI/UX improvement, try and avoid printing an extended traceback if diffoscope runs out of memory.

However:

> Note that because of the underlying memory management architecture (C’s
> malloc() function), the interpreter may not always be able to completely
> recover from this situation; it nevertheless raises an exception so that a
> stack traceback can be printed, in case a run-away program was the cause.

— https://docs.python.org/2/library/exceptions.html#exceptions.MemoryError