To avoid conflict with different liftIO from MonadIO (in some version of
yesod not the one I have here), and because it's generally clearer, since
this module has both Wai and Yesod stuff, to qualify them both.
Old 1.0.1 version is still supported as well. Cabal autodetects
which version is available, but in the Makefile, WITH_OLD_YESOD
has to be configured appropriately.
I have not squashed all the $newline warnings with the new Yesod.
They should go away eventually anyway as Yesod moves past that transition.
This avoids forking another process, avoids polling, fixes a race,
and avoids a rare forkProcess thread hang that I saw once time
when starting the webapp.
