Modified StatusLinePrinter to support standard error.
Modified StatusLinePrinter to support standard error.

We'll need to have StatusLinePrinter to support printing to standard
error for tunnel creation so that we can print the host parameters file
to standard output. This commit adds that functionality.

Signed-off-by: Jacob Howard <f862f167b85d41b225785c70d70808bc7337c1fe@havoc.io>

havoc-io/mutagen,havoc-io/mutagen