offAny typings must support no arguments

[clewisln]

When using TypeScript, it is currently not possible to remove all any listeners using ee.offAny(), becuase the typings require a listener to be passed in:

export declare class EventEmitter2 {
    offAny(listener: ListenerFn): this;
}

ee.offAny() //compile error

This should also include void, so that no arguments may be used:

export declare class EventEmitter2 {
    offAny(listener: ListenerFn | void): this;
}

ee.offAny() //now allowed