add liftH shim between yesod versions, to avoid needing zillions of ifdefs

Utility/Yesod.hs

@@ -1,11 +1,14 @@
 {- Yesod stuff, that's typically found in the scaffolded site.
  -
- - Copyright 2012 Joey Hess <joey@kitenet.net>
+ - Also a bit of a compatability layer to make it easier to support yesod
+ - 1.1 and 1.2 in the same code base.
+ -
+ - Copyright 2012, 2013 Joey Hess <joey@kitenet.net>
  -
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-{-# LANGUAGE CPP #-}
+{-# LANGUAGE CPP, RankNTypes #-}
 
 module Utility.Yesod where
 
@@ -16,6 +19,9 @@ import Language.Haskell.TH.Syntax
 import Data.Default (def)
 import Text.Hamlet
 #endif
+#if MIN_VERSION_yesod_default(1,2,0)
+import Yesod.Core
+#endif
 
 widgetFile :: String -> Q Exp
 #if ! MIN_VERSION_yesod_default(1,1,0)
@@ -31,3 +37,12 @@ widgetFile = widgetFileNoReload $ def
 hamletTemplate :: FilePath -> FilePath
 hamletTemplate f = globFile "hamlet" f
 #endif
+
+{- Lift Handler to Widget -}
+#if ! MIN_VERSION_yesod(1,2,0)
+liftH :: forall t. Lift t => t -> Q Exp
+liftH = lift
+#else
+liftH :: Monad m => HandlerT site m a -> WidgetT site m a
+liftH = liftH
+#endif