CKEDITOR.on('dialogDefinition', function(ev) {
    var dialogName = ev.data.name;
    var dialogDefinition = ev.data.definition;

    /* check if the definition is from the link dialog */
    if (dialogName == 'link') {
        /* get a reference to the "Target" tab and set default to '_blank' */
        var targetTab = dialogDefinition.getContents('target');
        var targetField = targetTab.get('linkTargetType');
        targetField['default'] = '_blank';

    } else if (dialogName == 'image') {
        var infoTab = dialogDefinition.getContents('info');
        /* remove unnecessary widgets/elements from the 'Image Info' tab */
        //infoTab.remove('txtHSpace');
        //infoTab.remove('txtVSpace');

        /* set default image target to _blank */
        var linkTab = dialogDefinition.getContents('Link');
        var targetField = linkTab.get('cmbTarget');
        targetField['default'] = '_blank';
    }
});