remove Params constructor from Utility.SafeCommand

This removes a bit of complexity, and should make things faster
(avoids tokenizing Params string), and probably involve less garbage
collection.

In a few places, it was useful to use Params to avoid needing a list,
but that is easily avoided.

Problems noticed while doing this conversion:

	* Some uses of Params "oneword" which was entirely unnecessary
	  overhead.
	* A few places that built up a list of parameters with ++
	  and then used Params to split it!

Test suite passes.

Command/Log.hs

@@ -148,7 +148,11 @@ getLog key os = do
 	config <- Annex.getGitConfig
 	let logfile = p </> locationLogFile config key
 	inRepo $ pipeNullSplitZombie $
-		[ Params "log -z --pretty=format:%ct --raw --abbrev=40"
+		[ Param "log"
+		, Param "-z"
+		, Param "--pretty=format:%ct"
+		, Param "-raw"
+		, Param "--abbrev=40"
 		, Param "--remove-empty"
 		] ++ os ++
 		[ Param $ Git.fromRef Annex.Branch.fullname

Command/Unannex.hs

@@ -72,7 +72,14 @@ start file key = stopUnless (inAnnex key) $ do
 performIndirect :: FilePath -> Key -> CommandPerform
 performIndirect file key = do
 	liftIO $ removeFile file
-	inRepo $ Git.Command.run [Params "rm --cached --force --quiet --", File file]
+	inRepo $ Git.Command.run
+		[ Param "rm"
+		, Param "--cached"
+		, Param "--force"
+		, Param "--quiet"
+		, Param "--"
+		, File file
+		]
 	next $ cleanupIndirect file key
 
 cleanupIndirect :: FilePath -> Key -> CommandCleanup
@@ -108,7 +115,14 @@ cleanupIndirect file key = do
 performDirect :: FilePath -> Key -> CommandPerform
 performDirect file key = do
 	-- --force is needed when the file is not committed
-	inRepo $ Git.Command.run [Params "rm --cached --force --quiet --", File file]
+	inRepo $ Git.Command.run
+		[ Param "rm"
+		, Param "--cached"
+		, Param "--force"
+		, Param "--quiet"
+		, Param "--"
+		, File file
+		]
 	next $ cleanupDirect file key
 
 {- The direct mode file is not touched during unannex, so the content

Command/Uninit.hs

@@ -37,7 +37,7 @@ check = do
   where
 	current_branch = Git.Ref . Prelude.head . lines <$> revhead
 	revhead = inRepo $ Git.Command.pipeReadStrict
-		[Params "rev-parse --abbrev-ref HEAD"]
+		[Param "rev-parse", Param "--abbrev-ref", Param "HEAD"]
 
 seek :: CommandSeek
 seek ps = do