switch to the strict state monad

I had not realized what a memory leak the lazy state monad could be,
although I have not seen much evidence of actual leaking in git-annex.
However, if running git-annex on a great many files, this could matter.

The additional Utility.State.changeState adds even more strictness,
avoiding a problem I saw in github-backup where repeatedly modifying
state built up a huge pile of thunks.

Annex.hs

@@ -26,7 +26,7 @@ module Annex (
 	fromRepo,
 ) where
 
-import Control.Monad.State
+import Control.Monad.State.Strict
 import Control.Monad.Trans.Control (StM, MonadBaseControl, liftBaseWith, restoreM)
 import Control.Monad.Base (liftBase, MonadBase)
 import System.Posix.Types (Fd)
@@ -41,6 +41,7 @@ import qualified Types.Remote
 import Types.Crypto
 import Types.BranchState
 import Types.TrustLevel
+import Utility.State
 import qualified Utility.Matcher
 import qualified Data.Map as M
 
@@ -125,18 +126,6 @@ run s a = runStateT (runAnnex a) s
 eval :: AnnexState -> Annex a -> IO a
 eval s a = evalStateT (runAnnex a) s
 
-{- Gets a value from the internal state, selected by the passed value
- - constructor. -}
-getState :: (AnnexState -> a) -> Annex a
-getState = gets
-
-{- Applies a state mutation function to change the internal state. 
- -
- - Example: changeState $ \s -> s { output = QuietOutput }
- -}
-changeState :: (AnnexState -> AnnexState) -> Annex ()
-changeState = modify
-
 {- Sets a flag to True -}
 setFlag :: String -> Annex ()
 setFlag flag = changeState $ \s ->