Increased the number of rows in the css editor of subs to be more comfortable and easy to use.

Every time someone tries to edit the CSS of a subverse, he/she has to
expand it in order to see it, this was due to a lack of rows in the
TextArea, but I made a small enough change to make it reasonable sized. 

![image](https://cloud.githubusercontent.com/assets/7976220/3459460/e55335fc-020c-11e4-9ebc-fe83b7c33989.png)

I know it's a tiny update but it's simple and makes a big difference :)