Ability to redirect stdout and stderr (tee program output)

[DonJayamanne]

The functionality provided by the RedirectOutput debug option in hew older version of PTVSD doesn't seem to be supported by the PyDev debugger.

From what I can tell this functionality is only available in attach scenarios. I guess this is because the debugger (PyDev) is always launched inside a terminal.

FYI - We're also missing the corresponding protocol implementation in the wrapper. I tried implementing this, however it was a moot point as there's no way to launch a program with redirection enabled as there's no way to do this in PyDev (I could be mistaken).