prevent default on catched events

Prevent default events.

Example with code : 
``` html
<a href="#" jb-link="file.html" jb-wrapper="#wrapper">Click me!</a>
```
Won't send user at # anchor on the page.

__If you accept the merge, I recommand you to add a patch version (_2.0.1_) on `jquery.js-binder.js` and `jquery.js-binder.min.js` headlines before merging__