Bugfixes

1) Fixed input field for the calendar ID

2) Adjusted width and height of the images so that they don't overflow outside the XBlock div

3) Enabled reseting the value to default in studio modal
Problem is in the way XBlocks load javascript files in the first place. If I understood the way that works, that function will be assigned but not executed on the first load. It will be executed only when the reloading takes place. I struggled with that myself when I was making my very first XBlock. If you have any idea how we could go around that, I'm happy to change it.