Lock roles 'vsite admin' and 'content editor'.

#4636


Before:
![locked-before](https://f.cloud.github.com/assets/3273122/1700461/8fdbf58c-6018-11e3-8593-b39b94220d42.png)




After:
![locked-after](https://f.cloud.github.com/assets/3273122/1700462/9202258e-6018-11e3-8ac1-94c05732bbd4.png)