Revert "Clean up direct mode cache and mapping info when dropping keys."

This reverts commit 57780cb3a4.

This was buggy, it caused the direct mode cache to be lost when dropping
keys, so when the file is gotten back, it's stored in indirect mode.

Note to self: Do not attempt bug fixes at 6 am!

Annex/Content/Direct.hs

@@ -15,6 +15,7 @@ module Annex.Content.Direct (
 	updateInodeCache,
 	writeInodeCache,
 	compareInodeCache,
+	removeInodeCache,
 	toInodeCache,
 ) where
 
@@ -119,5 +120,11 @@ writeInodeCache key cache = withInodeCacheFile key $ \f -> do
 	createContentDir f
 	liftIO $ writeFile f $ showInodeCache cache
 
+{- Removes an inode cache. -}
+removeInodeCache :: Key -> Annex ()
+removeInodeCache key = withInodeCacheFile key $ \f -> do
+	createContentDir f -- also thaws directory
+	liftIO $ nukeFile f
+
 withInodeCacheFile :: Key -> (FilePath -> Annex a) -> Annex a
 withInodeCacheFile key a = a =<< inRepo (gitAnnexInodeCache key)