added padding on UL and removed relative position on LI in column menu

Hello.
I was just having trouble with the relative position on LI if we already have a CSS design for LI that remove list-style and padding:  the relative position make the checkbox go out of the frame of the column menu.

But we don't need the relative position i we remove the padding, and it does not interfere with other design.
Could you take a look of that very small modification (and it is also my first pull request and i hope it respect the needed standards)