split out three modules from Git

Constructors and configuration make sense in separate modules.
A separate Git.Types is needed to avoid cycles.

Git/Types.hs

@@ -0,0 +1,36 @@
+{- git data types
+ -
+ - Copyright 2010,2011 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Git.Types where
+
+import Network.URI
+import qualified Data.Map as M
+
+{- There are two types of repositories; those on local disk and those
+ - accessed via an URL. -}
+data RepoLocation = Dir FilePath | Url URI | Unknown
+	deriving (Show, Eq)
+
+data Repo = Repo {
+	location :: RepoLocation,
+	config :: M.Map String String,
+	remotes :: [Repo],
+	-- remoteName holds the name used for this repo in remotes
+	remoteName :: Maybe String 
+} deriving (Show, Eq)
+
+{- A git ref. Can be a sha1, or a branch or tag name. -}
+newtype Ref = Ref String
+	deriving (Eq)
+
+instance Show Ref where
+	show (Ref v) = v
+
+{- Aliases for Ref. -}
+type Branch = Ref
+type Sha = Ref
+type Tag = Ref