Added functions to check call counts

Jasmine equivalents:
`.calls.any()`
http://jasmine.github.io/2.0/introduction.html#section-23

`.calls.count()`
http://jasmine.github.io/2.0/introduction.html#section-24

Example tests:
    var spyEvent = spyOnEvent('#some_element', 'click');
    expect(spyEvent.calls.any()).toEqual(false);
    $('#some_element').click();
    expect(spyEvent.calls.count()).toEqual(1);