Add keyword for the typed constructor of this

[trkjgrdg]

Consider the following classes:

class Animal {
    static verb = "moved";
    move() { alert("Animal " + Animal.verb); }
}

class Snake extends Animal {
    static verb = "slithered"; 
}

(new Snake()).move();

The above prints "Animal moved" because we hardcoded Animal.name in move. To make subclasses work properly, we should instead define move as:

move() { alert("Animal " + (<typeof Animal>this.constructor).verb); }

But using (<typeof Animal>this.constructor).verb everywhere is very verbose. It would be nice if there were a keyword (e.g. reuse class) that stood for <typeof Animal>this.constructor, so we could write just class.verb.

[trkjgrdg]

Related stackoverflow questions:
http://stackoverflow.com/questions/33387318/access-to-static-properties-via-this-constructor-in-typescript
http://stackoverflow.com/questions/29244119/how-to-access-static-members-from-instance-methods-in-typescript
http://stackoverflow.com/questions/34502195/using-static-property-in-inherited-class-method

[RyanCavanaugh]

See #3841/ #4356.