No need for separate injection object for Item.extend()
Change straps.js to directly use initialize() as constructor function rather than redirecting calls to it.

Should yield some interesting performance improvements.
Finally found a better and faster alternative for this.base() calls, by setting base on the function object instead.

base can be accessed on named functions very easily, leading to another measurable speed increase. Finally all performance reasons against straps.js are eliminated!
Solve issue with SVG gradients on Firefox.
Merge git://github.com/paperjs/paper.js