Allow click toggling of coffin drawer

[codekipple]

Small change in relation to this issue: https://github.com/fat/coffin/issues/2

Now i can have both a close button inside the drawer and a menu button to open the drawer. Swiping is better but i think many of my users will miss the menu without a toggler.

Not sure if this is something you'd be ok with i just needed it myself.