Range slider triggers false change event

[sfornengo]

Range slider generate false (and too many) change event:
http://jsbin.com/huvoraba/100/edit?html,js,console,output
As the mouse drag the slider cursor there are many change events triggered (at least under chromium) although the slider value is not changing at each mousemove event multiple change events seems to be triggered.
This create slowdown and difficulties to drag slider if the function bound to change event is greedy.