lift types from IO to Annex

Some remotes like External need to run store and retrieve actions in Annex,
not IO. In order to do that lift, I had to dive pretty deep into the
utilities, making Utility.Gpg and Utility.Tmp be partly converted to using
MonadIO, and Control.Monad.Catch for exception handling.

There should be no behavior changes in this commit.

This commit was sponsored by Michael Barabanov.

Utility/Tmp.hs

@@ -9,11 +9,12 @@
 
 module Utility.Tmp where
 
-import Control.Exception (bracket)
 import System.IO
 import System.Directory
 import Control.Monad.IfElse
 import System.FilePath
+import Control.Monad.IO.Class
+import Control.Monad.Catch (bracket, MonadMask)
 
 import Utility.Exception
 import Utility.FileSystemEncoding
@@ -42,18 +43,18 @@ viaTmp a file content = bracket setup cleanup use
 
 {- Runs an action with a tmp file located in the system's tmp directory
  - (or in "." if there is none) then removes the file. -}
-withTmpFile :: Template -> (FilePath -> Handle -> IO a) -> IO a
+withTmpFile :: (MonadIO m, MonadMask m) => Template -> (FilePath -> Handle -> m a) -> m a
 withTmpFile template a = do
-	tmpdir <- catchDefaultIO "." getTemporaryDirectory
+	tmpdir <- liftIO $ catchDefaultIO "." getTemporaryDirectory
 	withTmpFileIn tmpdir template a
 
 {- Runs an action with a tmp file located in the specified directory,
  - then removes the file. -}
-withTmpFileIn :: FilePath -> Template -> (FilePath -> Handle -> IO a) -> IO a
+withTmpFileIn :: (MonadIO m, MonadMask m) => FilePath -> Template -> (FilePath -> Handle -> m a) -> m a
 withTmpFileIn tmpdir template a = bracket create remove use
   where
-	create = openTempFile tmpdir template
-	remove (name, handle) = do
+	create = liftIO $ openTempFile tmpdir template
+	remove (name, handle) = liftIO $ do
 		hClose handle
 		catchBoolIO (removeFile name >> return True)
 	use (name, handle) = a name handle