map/isomap: changed quads table to weak
Must specify a viewing range now and changed setViewport
to accept tile ranges as arguments
Set the viewing range when loading map
loader: store map data as an array and also store non map layers as dummy table
Moved viewing range to a table
Renamed setViewport to setViewRange
Reuse map constructor for isomap
Added new methods for tmx compatibility:
getTileOffsets
getOpacity
getTilesetProperty
setTilesetProperty
getLayerProperty
setLayerProperty
getLayerName
getAtlas
Corrected flipping when loading and saving(for real)