expose debug as default export
expose debug as default export

+ Similar to tj/co/blob/master/index.js
+ Allow to re-export debug from another module in ES6
zacronos/debug,jabaz/debug,jabaz/debug,zacronos/debug,CantemoInternal/debug,CantemoInternal/debug,visionmedia/debug,elliottsj/debug,elliottsj/debug