map format: turns out more things are optional

the unhelpfulness of the spec is slowly starting to grate …

Anyways, apparently a lot more properties don't have to be present, and
you find out by finding maps somewhere that work but currently fail the
parser.

lib/Tiled2.hs

@@ -97,13 +97,13 @@ data Object = Object { objectId         :: Int
                        -- ^ Width in pixels. Ignored if using a gid.
                      , objectHeight     :: Double
                        -- ^ Height in pixels. Ignored if using a gid.
-                     , objectName       :: String
+                     , objectName       :: Maybe String
                        -- ^ String assigned to name field in editor
                      , objectType       :: String
                        -- ^ String assigned to type field in editor
-                     , objectProperties :: Map Text Text
+                     , objectProperties :: Maybe Value
                        -- ^ String key-value pairs
-                     , objectVisible    :: Bool
+                     , objectVisible    :: Maybe Bool
                        -- ^ Whether object is shown in editor.
                      , objectX          :: Double
                        -- ^ x coordinate in pixels
@@ -113,13 +113,13 @@ data Object = Object { objectId         :: Int
                        -- ^ Angle in degrees clockwise
                      , objectGid        :: Maybe GlobalId
                        -- ^ GID, only if object comes from a Tilemap
-                     , objectEllipse    :: Bool
+                     , objectEllipse    :: Maybe Bool
                        -- ^ Used to mark an object as an ellipse
                      , objectPolygon    :: Maybe (Vector (Double, Double))
                        -- ^ A list of x,y coordinates in pixels
                      , objectPolyline   :: Maybe (Vector (Double, Double))
                        -- ^ A list of x,y coordinates in pixels
-                     , objectText       :: Map Text Text
+                     , objectText       :: Maybe Value
                        -- ^ String key-value pairs
                      } deriving (Eq, Generic, Show)
 
@@ -276,7 +276,7 @@ instance ToJSON Tileset where
 
 
 -- | The full monty.
-data Tiledmap = Tiledmap { tiledmapVersion          :: Float
+data Tiledmap = Tiledmap { tiledmapVersion          :: Value
                            -- ^ The JSON format version
                          , tiledmapTiledversion     :: String
                            -- ^ The Tiled version used to save the file