Fixed Controller.isActive

I've updated jME to only call update on a Controller if isActive returns true.  I've also modified all the controllers in jME to not manually have to check anymore.

This should not effect your code in any way except if you've written any custom controllers you can take out any isActive checks.  It may also solve a lot of problems in your code if you were expecting this check to have been done before calling update. :wink: