reorder repo parameters last

Many functions took the repo as their first parameter. Changing it
consistently to be the last parameter allows doing some useful things with
currying, that reduce boilerplate.

In particular, g <- gitRepo is almost never needed now, instead
use inRepo to run an IO action in the repo, and fromRepo to get
a value from the repo.

This also provides more opportunities to use monadic and applicative
combinators.

Config.hs

@@ -16,19 +16,17 @@ type ConfigKey = String
 {- Changes a git config setting in both internal state and .git/config -}
 setConfig :: ConfigKey -> String -> Annex ()
 setConfig k value = do
-	g <- gitRepo
-	liftIO $ Git.run g "config" [Param k, Param value]
+	inRepo $ Git.run "config" [Param k, Param value]
 	-- re-read git config and update the repo's state
-	g' <- liftIO $ Git.configRead g
-	Annex.changeState $ \s -> s { Annex.repo = g' }
+	newg <- inRepo $ Git.configRead
+	Annex.changeState $ \s -> s { Annex.repo = newg }
 
 {- Looks up a per-remote config setting in git config.
  - Failing that, tries looking for a global config option. -}
 getConfig :: Git.Repo -> ConfigKey -> String -> Annex String
 getConfig r key def = do
-	g <- gitRepo
-	let def' = Git.configGet g ("annex." ++ key) def
-	return $ Git.configGet g (remoteConfig r key) def'
+	def' <- fromRepo $ Git.configGet ("annex." ++ key) def
+	fromRepo $ Git.configGet (remoteConfig r key) def'
 
 remoteConfig :: Git.Repo -> ConfigKey -> String
 remoteConfig r key = "remote." ++ fromMaybe "" (Git.repoRemoteName r) ++ ".annex-" ++ key
@@ -87,7 +85,5 @@ getNumCopies v =
 	Annex.getState Annex.forcenumcopies >>= maybe (use v) (return . id)
 	where
 		use (Just n) = return n
-		use Nothing = do
-			g <- gitRepo
-			return $ read $ Git.configGet g config "1"
+		use Nothing = read <$> fromRepo (Git.configGet config "1")
 		config = "annex.numcopies"