fixes #7608 - Override all puppetclass parameters in one click

proposed patch for #7608 adding a link on the puppetclasses page to set all parameters of the selected class to overriden
Oh sorry, you are right, you want to make sure there are no false params. 
Try ```puppetclass.class_params.map(&:override).all?``` , [```.all?```](http://ruby-doc.org/core-1.9.3/Enumerable.html#method-i-all-3F)