Fix warp pong
Use auto-update in Warp
Control.Reaper
Use Control.Reader for Timeout and FdCache
Merge pull request #276 from yesodweb/warp-auto-update

Use auto-update in Warp
removing a warning.
sectioning the document
refactoring for auto-update.
adding comments.
sectioning the document.
flatten reaper.
better naming.
sorting imports.
removing lang ext.
better naming.
using State instead of Maybe.
updating doc.
refining comment.
Rename reaper to mkReaper (thanks @kazu-yamamoto)
Fix previous rebase