Fixed bug in Wysiwyg activation button: css-class disabled was being added twice, because adminhtml/block/widget/button adds css-class disabled if button is disabled and catalog/helper/form/wysiwyg adds css-class disabled too.
Merge pull request #195 from magento/michaelscheel-MAGE-6165

Fixed bug in Wysiwyg activation button: css-class disabled was being add...