Method (scrollByDirection) that allows a user to scroll current top/bottom/left/right +/- x pixels

Hi,

Nice plugin.

I've added a method 'scrollByDirection' that takes a string ('up', 'down', 'left', 'right') and an options objects where it is possible to define the amount to scroll in the given direction each time the method is called.

Hope that you will include it in your plugin so I can upgrade to future versions easily :)

Cheers,
Joachim