dunai: Group imports (KSG Haskell 1.3.0 - 3.5). Refs #285.

Imports should be grouped between external imports, external imports
from the same project (but different libraries) and internal imports.
When groups are used, comments must be used to indicate the nature of
each group.

dunai/src/Control/Monad/Trans/MSF/List.hs

@@ -8,14 +8,14 @@ module Control.Monad.Trans.MSF.List
   , module Control.Monad.Trans.List
   ) where
 
--- External
+-- External imports
 #if !MIN_VERSION_base(4,8,0)
 import Control.Applicative ((<$>))
 #endif
 
 import Control.Monad.Trans.List hiding (liftCallCC, liftCatch)
 
--- Internal
+-- Internal imports
 import Data.MonadicStreamFunction.InternalCore (MSF (MSF, unMSF))
 
 -- * List monad