Modal editor close button

Request from Mona: change 'X' to 'Save and Close' in the modal function editing experience.

Before:
![screen shot 2014-11-20 at 11 52 40 am](https://cloud.githubusercontent.com/assets/413693/5131833/c9f5d8f6-70ab-11e4-9f18-771300108cad.png)
After:
![screen shot 2014-11-20 at 11 50 43 am](https://cloud.githubusercontent.com/assets/413693/5131818/9889f734-70ab-11e4-92ea-97c0faa913c0.png)