"class" attributes (for jquery {} notation) need to get wrapped in quotes for ie8

My ie8/xp virtual machine freaks out at the word **class**, if it's not explicitly a string.
![screen shot 2014-12-17 at 11 14 50 pm](https://cloud.githubusercontent.com/assets/3149184/5484696/8e9e0b00-8642-11e4-8476-c5be27f1e776.png)

````javascript
t.$box = $('<div/>', {
  class: pfx + 'box ' + pfx + t.o.lang + ' trumbowyg'
 });
````

Needs to be: ````'class': pfx + 'box ' + pfx + t.o.lang + ' trumbowyg'````

Otherwise, works great!