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.

Build/DistributionUpdate.hs

@@ -130,11 +130,13 @@ makeinfos updated version = do
 		]
 	void $ inRepo $ runBool
 		[ Param "annex"
-		, Params "move --to website"
+		, Param "move"
+		, Param "--to"
+		, Param "website"
 		]
 	void $ inRepo $ runBool
 		[ Param "annex"
-		, Params "sync"
+		, Param "sync"
 		]
 	
 	-- Check for out of date info files.