.d.ts generation should use Date instead of Windows.Foundation.DateTime and number instead of Windows.Foundation.TimeSpan

[nichamp]

For example, Windows.Foundation.PropertyValue:

    abstract class PropertyValue {
        static createEmpty(): any;
        static createUInt8(value: number): any;
        static createInt16(value: number): any;
        static createUInt16(value: number): any;
        static createInt32(value: number): any;
        static createUInt32(value: number): any;
        static createInt64(value: number): any;
        static createUInt64(value: number): any;
        static createSingle(value: number): any;
        static createDouble(value: number): any;
        static createChar16(value: string): any;
        static createBoolean(value: boolean): any;
        static createString(value: string): any;
        static createInspectable(value: any): any;
        static createGuid(value: string): any;
        static createDateTime(value: Windows.Foundation.DateTime): any;
        static createTimeSpan(value: Windows.Foundation.TimeSpan): any;
        static createPoint(value: Windows.Foundation.Point): any;
        static createSize(value: Windows.Foundation.Size): any;
        static createRect(value: Windows.Foundation.Rect): any;
        static createUInt8Array(value: number[]): any;
        static createInt16Array(value: number[]): any;
        static createUInt16Array(value: number[]): any;
        static createInt32Array(value: number[]): any;
        static createUInt32Array(value: number[]): any;
        static createInt64Array(value: number[]): any;
        static createUInt64Array(value: number[]): any;
        static createSingleArray(value: number[]): any;
        static createDoubleArray(value: number[]): any;
        static createChar16Array(value: string[]): any;
        static createBooleanArray(value: boolean[]): any;
        static createStringArray(value: string[]): any;
        static createInspectableArray(value: any): any;
        static createGuidArray(value: string[]): any;
        static createDateTimeArray(value: Windows.Foundation.DateTime[]): any;
        static createTimeSpanArray(value: Windows.Foundation.TimeSpan[]): any;
        static createPointArray(value: Windows.Foundation.Point[]): any;
        static createSizeArray(value: Windows.Foundation.Size[]): any;
        static createRectArray(value: Windows.Foundation.Rect[]): any;
    }