Merge pull request #19 from tirenatoanjos/patch-1

## Update jquery.balloon.js
### Enhancement
- Added an option to specify the tip position by rate.

jquery.balloon.js

@@ -137,8 +137,8 @@
       if(m) {
         balloon["set" + m.camel.pos.p1]
           (balloon[m.pos.p1] + ((m.isTopLeft) ? 1 : -1) * (options.tipSize - balloon["border" + m.camel.pos.o]));
-        makeTip(balloon, outerTip, m, options.tipSize, $balloon.css("border-" + m.pos.o + "-color"));
-        makeTip(balloon, innerTip, m, options.tipSize - 2 * balloon["border" + m.camel.pos.o], $balloon.css("background-color"));
+        makeTip(balloon, outerTip, m, options.tipSize, $balloon.css("border-" + m.pos.o + "-color"), options.tipPosition);
+        makeTip(balloon, innerTip, m, options.tipSize - 2 * balloon["border" + m.camel.pos.o], $balloon.css("background-color"), options.tipPosition);
         $balloon.data("outerTip", outerTip.$).data("innerTip", innerTip.$);
       } else {
         $.each([outerTip.$, innerTip.$], function() { this.remove(); });
@@ -152,7 +152,7 @@
         ["setBorder" + m.camel.pos.c1](len)
         ["setBorder" + m.camel.pos.c2](len)
         ["set" + m.camel.pos.p1]((m.isTopLeft) ? -tipSize : balloon.inner[m.size.p])
-        ["set" + m.camel.pos.c1](balloon.inner[m.size.c] / 2 - len)
+        ["set" + m.camel.pos.c1](balloon.inner[m.size.c] / tipPosition - len)
         .active()
         .$.css("border-" + m.pos.f + "-color", color);
     }
@@ -292,7 +292,7 @@
   $.balloon = {
     defaults: {
       contents: null, url: null, ajaxComplete: null, classname: null,
-      position: "top", offsetX: 0, offsetY: 0, tipSize: 12,
+      position: "top", offsetX: 0, offsetY: 0, tipSize: 12, tipPosition: 2,
       delay: 0, minLifetime: 200, maxLifetime: 0,
       showDuration: 100, showAnimation: null,
       hideDuration:  80, hideAnimation: function(d, c) { this.fadeOut(d, c); },