Don't use Raw for serving static directories.

[jkarni]

Raw has problems (see in particular #408 ) which we probably won't be able to fix. So as suggested by @kosmikus , we should at least try to move away from Raw for some common use cases. Static directory serving is the most obvious one.

[jkarni]

See also #350

[fosskers]

Currently being bit by this. I'd like to serve my own logo and project-local bootstrap. From my .cabal:

data-files:  assets/bootstrap.min.css
           , assets/highcharts.js
           , assets/jquery.js
           , assets/logo.png
           , assets/logo-small.png

and some lines from my server:

type API = ... :<|> "assets" :> Raw

server :: Server API
server = ... :<|> serveDirectory "assets"

This used to work fine, but broke recently. Now all my assets 404.