draw ground layer when navigating other floors

[lucasterra]

Drawing groundlayer is disabled by default.

You can enable it by either setting TibiaMap.drawGroundLayer to true

this.drawGroundLayer = true;

Or by calling TibiaMap.setDrawGroundLayer at runtime. This allows you to make a control button to enable or disable it.

var map = new TibiaMap();
...
map.setDrawGroundLayer(true);