lib.dom.d.ts includes bad IE11 defn's

[alexeagle]

The section
IE11 ECMAScript Extensions
(https://github.com/Microsoft/TypeScript/blob/master/bin/lib.dom.d.ts#L636)
contains eg.

declare var Map: {
    new <K, V>(): Map<K, V>;
    prototype: Map<any, any>;
}

But the spec says that Map should have a copy constructor:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map

This causes compile errors for projects which use that constructor. (eg. Angular)

[mhegazy]

Fixed in #2739