Updated adl API. Added experimental Cu.decorator method.
Experimental tweening library.
Renamed dom.position => dom.offset, dom.childIndex => dom.index.
event.stopEvent => event.stop, event.viewportArea => event.viewport,
event.getXY => event.offset.

Fixed 1. decorator. 2. ajax 1223 status code on IE8. 3. Addons that used
older syntax.

Introduced Cu.select and Cu("seelctor"). Uses querySelectorAll by
default.

Moved object.traverse as addon.

Removed array.inArray.

Introduced copper.prototype.js.
Replaced Cu.object.mixin and Cu.object.copyTo with Cu.mix, with a
slightly different API.
Renamed Cu.listen and Cu.unlisten to Cu.on and Cu.off.
Moved object.clone and array.compact as addons.

Fixed spelling mistake at experimental template.js.