Remove dead code

[sol]

(I think this is just a duplication of
wai-middleware-static/Network/Wai/Middleware/Static.hs)

[coveralls]

Coverage remained the same when pulling 1d28b81 on remove-dead-code into ab04289 on master.

[xich]

wai-middleware-static/Network/Wai/Middleware/Static.hs is just a symlink to this file, so it's not dead code! ;-)

Though I tend to agree your comments in #108, we should just break wai-middleware-static out into it's own repo.