Renamed 'MapView' to 'MapViewport'. Added documentation to the maps module.

lib/pixi/bundle.js

@@ -62,7 +62,6 @@ window.FontInfo = FontInfo
 window.Text = Text
 
 //Maps
-import MapView from './maps/mapview.js'
 import { GeoMap, ImageMap, DeepZoomMap } from './maps/map.js'
 import { MapData, DeepZoomMapData } from './maps/mapdata.js'
 
@@ -80,7 +79,8 @@ window.Projection = {
     Robinson
 }
 
-window.MapView = MapView
+import MapViewport from './maps/mapviewport.js'
+window.MapViewport = MapViewport
 
 import MapApp from './maps/mapapp.js'