Improvements and some additional functionality

Hi OberstK,
as promised, I did some improvements to your javascript.
I added some comments to my changes and some questions.

I didn't know how much you actually know about Javascript...
If you want, I could expand on a few things.

Otherwise, have fun reviewing the request and have some nice LoL-Games :wink:
valentinouno.
It didn't tell me, for-of-loops are the fastest. for-of-loops are something I didn't know about either. :confused:
Consider the fact that for-in-loops, as you use them now, are a bit slower than the for-loop I used here.
I did the changes, because your defaultChampData-Array will get bigger with each new champion and I already experience a short loading time, when I load the data on the site.