multitouch improvements

tagetedtouch now works also with multitouch.
memory consumption of touch events improved.

added a Class named HashSet. A generic implementation of a Set with a optional maximum size. Used to store the touch events.

I have changed the touchTest a little bit to test it:
I added in TouchesTest.js

    this._drawNode = cc.DrawNode.create();
    this.addChild( this._drawNode, 10 );
    this.setTouchEnabled(true);

to ctor funktion

and added a function:

    onTouchesMoved:function (touches, event) {
        for (var k = touches.length - 1; k >= 0; k--) {
            this._drawNode.drawSegment( touches[k].getLocation(),touches[k].getPreviousLocation(), 10, cc.c4f(1, 0, 1, 0.5) );
        }
    },

with this you can test it.