fixed to use safe-iterative method & remove hasOwnProperty()

[kuna]

hi, I was searching for light venn diagram library and I found your work. first, thanks for your great work.
however, I found it wasn't working properly although it worked well in standalone example. I tried debugging and I found there was collision with jquery.bootstrap.js.
So my modification summarization:

1. use safe iterative method
   (don't use directionary-based iteration; because of Array.prototype)
2. hasOwnProperty() in handleVennClick()
   (it doesn't recognize offsetY attr existence, maybe some library overlapped)

After that it started to work properly with jquery & bootstrap combination. Also I minified edited js with javascript minifier.
Regards, kuna.

[sidoh]

Awesome. Thank you!