Update to new version of Hakyll.

Whew. I need to refactor this.

HakyllBibTex.hs

@@ -18,6 +18,7 @@ import           Data.Binary              (Binary (..))
 import           Data.Char                (isSpace)
 import           Data.List.Split          (splitOn)
 import           Data.List                (intercalate)
+import           Data.Map                 (empty)
 import           Data.Typeable            (Typeable)
 import           Hakyll
 import qualified Bibtex                   as B
@@ -38,13 +39,14 @@ instance Binary BibEntry where
     get = BibEntry <$> (B.Item <$> get <*> get <*> get)
 
 --------------------------------------------------------------------------------
+-- XXX refactor to use Context monoid XXX
 bibEntryContext :: Context BibEntry
 bibEntryContext = Context $ \key _ item ->
     let BibEntry t = itemBody item
     in case key of
         "identifier" -> return $ StringField $ B.identifier t
         _            -> case lookup key (B.fields t) of
-            Nothing  -> empty
+            Nothing  -> Control.Applicative.empty
             Just val -> case key of
                 "author" -> return $ StringField $ formatAuthors val
                 "month"  -> return $ StringField $ expandMonth val
@@ -62,6 +64,7 @@ bibFileEntryNames (BibFile es) = [B.identifier t | BibEntry t <- es]
 
 
 --------------------------------------------------------------------------------
+-- XXX refactor to use Text.CSL.readBiblioFile XXX
 parseBibFile :: String -> BibFile
 parseBibFile string = case Parsec.runParser (B.bibEntries <* Parsec.eof)
                            [] "<bib file>" string of
@@ -124,7 +127,8 @@ trimSpace = f . f
 --------------------------------------------------------------------------------
 latexToHtml tex =
     let p = case Pandoc.readLaTeX Pandoc.def tex of
-                Pandoc.Pandoc meta [Pandoc.Para para] ->
+                Right (Pandoc.Pandoc meta [Pandoc.Para para]) ->
                     Pandoc.Pandoc meta [Pandoc.Plain para]
-                x                                     -> x
+                Left _                                        ->
+                    Pandoc.Pandoc (Pandoc.Meta Data.Map.empty) []
     in Pandoc.writeHtmlString Pandoc.def p

site.hs

@@ -6,7 +6,6 @@ import           Hakyll
 import           HakyllBibTex
 import           System.Process
 import           Text.Pandoc.Options
-import           Text.Regex
 
 config :: Configuration
 config = defaultConfiguration