fix all remaining -Wincomplete-uni-patterns warnings

A couple of these were probably actual bugs in edge cases. Most of the
changes I'm fine with. The fact that aeson's object returns sometihng
that we know will be an Object, but the type checker does not know is
kind of annoying.

Command/MetaData.hs

@@ -119,8 +119,9 @@ perform c o k = case getSet o of
 cleanup :: Key -> CommandCleanup
 cleanup k = do
 	m <- getCurrentMetaData k
-	let Object o = toJSON' (MetaDataFields m)
-	maybeShowJSON $ AesonObject o
+	case toJSON' (MetaDataFields m) of
+		Object o -> maybeShowJSON $ AesonObject o
+		_ -> noop
 	showLongNote $ unlines $ concatMap showmeta $
 		map unwrapmeta (fromMetaData m)
 	return True