Removed JQuery dependency, should now work again FIXED

Switched to using pure JavaScript without depending on JQuery as asp.net seemed to interfere with certain method calls. Should now work on digirooster.hanze.nl and intranet.hanze.nl. No support for blackboard.hanze.nl as it has a different form layout. 

Now the commit history should be correct again. Also added an entry to [AUTHORS.txt](https://github.com/OrangeTux/HAL/blob/master/AUTHORS.txt).
Please remove whitesplace between `if` and `(form.addEventListener)`.