add SeekInput (not yet used)

No behavior changes (hopefully), just adding SeekInput and plumbing it
through to the JSON display code for later use.

Over the course of 2 grueling days.

withFilesNotInGit reimplemented in terms of seekHelper
should be the only possible behavior change. It seems to test as
behaving the same.

Note that seekHelper dummies up the SeekInput in the case where
segmentPaths' gives up on sorting the expanded paths because there are
too many input paths. When SeekInput later gets exposed as a json field,
that will result in it being a little bit wrong in the case where
100 or more paths are passed to a git-annex command. I think this is a
subtle enough problem to not matter. If it does turn out to be a
problem, fixing it would require splitting up the input
parameters into groups of < 100, which would make git ls-files run
perhaps more than is necessary. May want to revisit this, because that
fix seems fairly low-impact.

Command/FromKey.hs

@@ -45,27 +45,30 @@ seek o = case (batchOption o, keyFilePairs o) of
 		withPairs (commandAction . start force) ps
 
 seekBatch :: BatchFormat -> CommandSeek
-seekBatch fmt = batchInput fmt parse commandAction
+seekBatch fmt = batchInput fmt parse (commandAction . go)
   where
 	parse s = do
 		let (keyname, file) = separate (== ' ') s
 		if not (null keyname) && not (null file)
 			then do
 				file' <- liftIO $ relPathCwdToFile file
-				return $ Right $ go file' (keyOpt keyname)
+				return $ Right (file', keyOpt keyname)
 			else return $
 				Left "Expected pairs of key and filename"
-	go file key = starting "fromkey" (mkActionItem (key, toRawFilePath file)) $
-		perform key file
+	go (si, (file, key)) = 
+		let ai = mkActionItem (key, toRawFilePath file)
+		in starting "fromkey" ai si $
+			perform key file
 
-start :: Bool -> (String, FilePath) -> CommandStart
-start force (keyname, file) = do
+start :: Bool -> (SeekInput, (String, FilePath)) -> CommandStart
+start force (si, (keyname, file)) = do
 	let key = keyOpt keyname
 	unless force $ do
 		inbackend <- inAnnex key
 		unless inbackend $ giveup $
 			"key ("++ keyname ++") is not present in backend (use --force to override this sanity check)"
-	starting "fromkey" (mkActionItem (key, toRawFilePath file)) $
+	let ai = mkActionItem (key, toRawFilePath file)
+	starting "fromkey" ai si $
 		perform key file
 
 -- From user input to a Key.