Add support for Tiled 1.9

[SSBMTonberry]

Ref the Tiled TMX changelog some new changes must be supported in Tileson, including:

• The type attribute on tile and object is renamed to class. Must add support for maps created after this change.

• Add class attribute to map, tileset, layer, imagelayer, objectgroup, group, wangset and wangcolor.

  • Map
  • Tileset
  • Layer
  • ImageLayer
  • ObjectGroup
  • Group
  • WangSet
  • WangColor

• Add x, y, width and height attributes to the tile element, which store the sub-rectangle of a tile’s image used to represent this tile (By default the entire image is used).

• Add tilerendersize and fillmode attributes to the tileset element, which affect the way tiles are rendered.

• Make it possible to retrieve actual class information using getClass() when map is loaded through a TiledProject.