Adds support for multiple events on the same day

Excellent calendar but I needed support for multiple events on the same day so I implemented it.
Just specify an array of events. The old way still works.

I think I covered all the different way to specify events.

example:
 ```javascript
var events = {
    '11-07-2014': 'Old way still works',
    '11-08-2014': ['<a href="">event one</a>', '<span>event two</span>']
}
```