Don't catch unhandled exceptions in examples.

Allow importing when sys.stdout is reassigned on Python 3

ExceptionPexpect.__init__: invoke super's init

Correctly handle when select in spawn returns with an error (e.g. SIGWINCH...

This avoids an exception in the following:

        import pexpect
        import pickle
        pickle.loads(pickle.dumps(pexpect.EOF('hey you')))

Closes gh-30