v0.4.0

• Feature / BC break: The Stdio is now a well-behaving duplex stream
  (#35 by @clue)
• Feature / BC break: The Readline is now a well-behaving readable stream
  (#32 by @clue)
• Feature: Add Readline::getPrompt() helper
  (#33 by @clue)
• Feature / Fix: All unsupported special keys, key codes and byte sequences will now be ignored
  (#36, #30, #19, #38 by @clue)
• Fix: Explicitly redraw prompt on empty input
  (#37 by @clue)
• Fix: Writing data that contains multiple newlines will no longer end up garbled
  (#34, #35 by @clue)