Additions, fixes, enhancements (Chrome, Brasero)

Rebuilt Google Chrome base icon (realigned geometries to grid), recolore...d and added Beta and Unstable icons. Added google-chrome status icon (closes #784), added brasero status icon (based off new design).

Status:

![brasero](https://cloud.githubusercontent.com/assets/5674757/3054373/d1bae9fc-e1b6-11e3-9524-8d2e076f6138.png)
![google-chrome](https://cloud.githubusercontent.com/assets/5674757/3054374/d1bb301a-e1b6-11e3-84c7-cf29fb60c42a.png)

Icons:

![google-chrome](https://cloud.githubusercontent.com/assets/5674757/3054403/0a4d9f76-e1b7-11e3-9686-69c0e4b07cfc.png)
![google-chrome-beta](https://cloud.githubusercontent.com/assets/5674757/3054402/0a4d79ec-e1b7-11e3-9a44-73d98cb0a7c8.png)
![google-chrome-unstable](https://cloud.githubusercontent.com/assets/5674757/3054404/0a4ee87c-e1b7-11e3-958d-8a3d0dd99ca7.png)