CSS Coding Standards style.css file

According to http://make.wordpress.org/core/handbook/coding-standards/css/ 
Each selector should be on its own line

One example:
```
ol, ul {
list-style: none;
}
```
Should be:
```
ol, 
ul {
list-style: none;
}


https://github.com/Automattic/_s/issues/503