Attempt to improve launcher/dash icon

So, I tried to improve the launcher icon.
This icon is from the archlinux-artwork package, and can be found in /usr/share/archlinux/icons.
It fills the space a little bit better, and adds a little bit more contrast.
Here's some comparisons:

Side by side: 
![shutter-SS-4c9e](https://f.cloud.github.com/assets/1578270/121600/35e3244a-6dcc-11e2-98a8-67f699f9a006.png)

Before:
![shutter-SS-d416](https://f.cloud.github.com/assets/1578270/121602/42df309e-6dcc-11e2-834b-535f3b25d150.png)

After:
![shutter-SS-349b](https://f.cloud.github.com/assets/1578270/121603/50704644-6dcc-11e2-9cc7-7716f4f95659.png)