Cleanup: explicit is better than implicit
Add 'Valid x =>' to splitExtension(s) QuickCheck property (#34)
Refactor: don't use reverse explicitly (#6)

I couldn't decide between the different implementations of dropWhileEnd and
takeWhileEnd from https://ghc.haskell.org/trac/ghc/ticket/9623#comment:7, so I
choose the simplest solution using two times reverse instead of foldr. See
also:
https://www.haskell.org/pipermail/libraries/2014-September/023835.html
Merge pull request #35 from thomie/splitExtensions

Refactor and fix test for splitExtension(s)