move remote removal into separate module

This allows using Git.Remote w/o needing to have Git.BuildVersion, which
requires configure. It will simplify github-backup when these libraries are
used there.

Git/Remote/Remove.hs

@@ -0,0 +1,27 @@
+{- git remote stuff
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+{-# LANGUAGE CPP #-}
+
+module Git.Remote.Remove where
+
+import Common
+import Git
+import Git.Types
+import qualified Git.Command
+import qualified Git.BuildVersion
+
+remove :: RemoteName -> Repo -> IO ()
+remove remotename = Git.Command.run
+	[ Param "remote"
+	-- name of this subcommand changed
+	, Param $
+		if Git.BuildVersion.older "1.8.0"
+			then "rm"
+			else "remove"
+	, Param remotename
+	]