Removed gen.coroutine from ProcessLauncher.
Removed gen.coroutine from ProcessLauncher.

Chagned those decorated methdo to async ones and chagned shutdown
to synchronous.

Also raised NotImplementedError for FirenadoLauncher instead of
returning none.

Fixed: #402

piraz/firenado,piraz/firenado,piraz/firenado,candango/firenado,candango/firenado,candango/firenado