Option to add "Converted to outlines" version with bounding box
First off, thanks a ton for this plugin! Use this every day, very frequently.

One thing that would be amazing is the option to have the added icon (from the dialog) be converted to outlines and have a bounding box added as a layer below it automatically. 

Not everyone I work with has the fonts installed so when I share documents, it shows up as all question marks. I prefer to work with the vectors as well, but keep a maintained bounding box. What I do today is convert the icon to outlines, add a base at the bottom so I can maintain the container, and then folder it. I included a screenshot.

I would do a pull request if I knew enough about how to write in Cocoascript – maybe soon!

Cheers!
![screen shot 2016-04-19 at 10 37 03 am](https://cloud.githubusercontent.com/assets/6194928/14649232/f73ba056-061a-11e6-803e-13d2c478e9f9.png)
