Here’s a small plugin that you can use that alters the click handler to simulate a HTML anchor click including a target: http://jsfiddle.net/highcharts/ud795/RoB commented
I do not think skipping the credits is the right solution. The Highcharts credits can easily be disabled If someone does not want to display such information. But there are some of us who would still prefer to 'give credit where credit is due'!
As suggested, a 'permanent' option such as:
would be the perfect solution.
By the way, I could not get the above suggested pugin to work!