default opacity 0.67 (#36)

js/control/OpacitySlider.js

@@ -8,7 +8,7 @@ BR.OpacitySlider = L.Control.extend({
         var container = L.DomUtil.create('div', 'leaflet-bar control-slider'),
             input = $('<input id="slider" type="text"/>'),
             item = localStorage.opacitySliderValue,
-            value = item ? parseInt(item) : 100,
+            value = item ? parseInt(item) : BR.conf.defaultOpacity * 100,
             minOpacity = (BR.conf.minOpacity || 0) * 100;
 
         if (value < minOpacity) {