Get rid of mtl dependency (#133)

* Get rid of mtl dependency

* Put back mtl dependency

Author: ndmitchell

src/Development/IDE/Core/OfInterest.hs

@@ -14,7 +14,6 @@ module Development.IDE.Core.OfInterest(
     ) where
 
 import           Control.Concurrent.Extra
-import           Control.Monad.Except
 import Data.Hashable
 import Control.DeepSeq
 import GHC.Generics
@@ -27,6 +26,7 @@ import           Data.Set                                 (Set)
 import qualified Data.Set                                 as Set
 import qualified Data.Text as T
 import Data.Tuple.Extra
+import Data.Functor
 import           Development.Shake
 
 import           Development.IDE.Core.Shake

src/Development/IDE/Core/Rules.hs

@@ -25,7 +25,8 @@ module Development.IDE.Core.Rules(
     fileFromParsedModule,
     ) where
 
-import           Control.Monad.Except
+import Control.Monad
+import Control.Monad.Trans.Class
 import Control.Monad.Trans.Maybe
 import Development.IDE.Core.Compile
 import Development.IDE.Types.Options

src/Development/IDE/Core/Service.hs

@@ -20,8 +20,8 @@ module Development.IDE.Core.Service(
 
 import           Control.Concurrent.Extra
 import           Control.Concurrent.Async
-import           Control.Monad.Except
 import Development.IDE.Types.Options (IdeOptions(..))
+import Control.Monad
 import           Development.IDE.Core.FileStore
 import           Development.IDE.Core.OfInterest
 import Development.IDE.Types.Logger