Merge pull request #389 from aiduryagin/master

fix error "Invalid argument." in IE8

Author: IonDen

js/ion.rangeSlider.js

@@ -2177,7 +2177,10 @@
 
             for (i = 0; i < num; i++) {
                 label = this.$cache.grid_labels[i][0];
-                label.style.marginLeft = -this.coords.big_x[i] + "%";
+
+                if (this.coords.big_x[i] !== Number.POSITIVE_INFINITY) {
+                    label.style.marginLeft = -this.coords.big_x[i] + "%";
+                }
             }
         },