BoxBox CEO Aaron LevieCloud-based enterprise storage company Box opened at $20.2o, up 44%.Its IPO was priced at $14.It's now up 52%, to $21.44.It's a nice pop for a company that had a lot of negativity surrounding its IPO.Box's revenue growth has been slowing down. In the third quarter of 2014, revenue was up 70%. But that's down from 81% in the prior quarter. And that's down from 94% in the quarter prior...